Descriptive statistics, Statistics 2022

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For a linear regression equation, the sum of the squared residuals can be computed directly by finding the difference between each Y and its predicted Y, then squaring the difference and adding the squared values. An alternative procedure is to calculate __________. (1 - r2)(SSY) (SSY)(SSX) r2 (SSY) (1 + r2)(SSY)

(1 - r2)(SSY)

Which of the following values of the correlation coefficient indicates the WEAKEST relationship between two variables?

+0.25

In an independent-measures experiment with three treatment conditions has a sample of n = 10 scores in each treatment. If all three treatments have the same total, T1 = T2 = T3, what is SSbetween?

when conducting a hypothesis test for the Pearson correlation coefficient, a researcher is testing the null hypothesis that the correlation value is?

which of these values of the correlation coefficients indicates the weakest relationship between two variables?

0.03

According to Cohen's guidelines presented in your text, a correlation value of _____ is considered small, _____ as medium, and _____ as large.

0.10; 0.30; 0.50

a coefficient alpha of _____ is considered a minimally acceptable level of reliability for measures that will be used to make decisions about individuals based on their scores on the measure

0.90

For a research study with 2 levels of factor A, 3 levels of factor B, and n = 5 in each treatment condition, what are the df values for the F-ratio evaluating the main effect for factor A?

1, 24

For a research study with two levels of factor A, three levels of factor B, and n=5 in each treatment condition, what are the df values for the F-ratio evaluating the main effects for factor A? 1, 24 1, 4 1, 29 2, 29

1, 24 (Specifically, MS(A) = k-1 for factor A = 2 levels - 1 = 1. The MS(within-treatments) for the study is the sum of the df's for each of the six treatment groups of n=5 -- hence, 6 * (5-1) = 24.)

On average, what value is expected for the F-ratio if the null hypothesis is true?

1.00

a perfect linear relationship will yield a Pearson correlation value of?

1.00 or 1.00

"F(2,27) = 8.62, p < .01. how many participants in each treatment?

In analysis of variance, with 3 treatment conditions and a dftotal of 32. number of individuals per sample?

For the following data, what is the value of SS(B)? B1 B2 A1 n = 5 n= 5 M = 1 M = 2 SS = 10 SS = 20 A2 n = 5 n= 5 M = 1 M = 4 SS = 10 SS = 20

For the following data, what is the value of SSB? B1; B2; A1; n = 5; M = 1; SS = 10; n = 5; M = 2; SS = 20; A2; n = 5; M = 1; SS = 10; n = 5; M = 4; SS = 20

a Pearson correlation coefficient is calculated for 48 individuals. What value of df should be used to determine statistical significance in hypothesis testing?

46 (N-2)

A research study comparing three treatments with n = 5 in each treatment produces T1 = 5, T2 = 10, T3 = 15, with SS1 = 6, SS2 = 9, SS3 = 6, and ΣX(squared) = 94. For this study, what is SS(between)?

An analysis of variances produces SS(total) = 80 and SS(within) = 30. For this analysis, what is the SS(between)?

50 80-30

For the regression equation Y = 2X - 3, if the mean for X is MX = 5, what is the mean for Y?

7 Because the point (MX, MY) always lies on the regression line, we can simply solve for MY = b*MX + a = 2*5 - 3 = 7.

A repeated-measures ANOVA with n = 5 subjects has df within-treatment equal to 12. What is the value for dferror for this analysis?

For the regression equation Y = X - 2, if the mean for Y is MY = 6, what is the mean for X?

8 MY = b*MX + a, so 6 = 1*MX - 2, so MX = 8.

A research report concludes that there are significant differences among treatments, with "F(2, 24) = 8.62, p < .01." If the same number of participants was used in all of the treatment conditions, then how many individuals were in each treatment?

Researchers who study the process of reading in children have discovered that better readers make smoother eye movements across the page (e.g., there is a positive correlation between reading skill and the smoothness of the eye movements). Which of the following is a possible cause of this correlation between smooth eye movements and reading ability?

All of these options are possible causes of the correlation.

An analysis of variances produce SSbetween = 20, SSwithin = 30, and an F-ratio with df = 2, 15. For this analysis, what is the F-ratio? A. 20/30 = 0.67 B. 10/2 = 5.0 C. 30/20 = 1.5 D. 2/10 = 0.20

In an analysis of variance, differences caused by treatment effects contribute to which of the following variances?

Between-treatments variance but not within-treatments variance

A research report with a single-factor ANOVA concludes that there are significant differences among treatments, with F(2, 27) = 8.62, p < .01. If the same number of participants was used in all of the treatment conditions, then how many individuals were in each treatment? A. 7 B. 9 C. 10 D. cannot determine without additional information

A two-factor research study is used to evaluate the effectiveness of a new blood-pressure medication. In this two-factor study, Factor A is a medication versus no medication and factor B is male versus female. The medicine is expected to reduce blood pressure for both males and females, but it is expected to have a much greater effect for males. This expectation should result in ___. A. a significant main effect for factor A (medication) B. a significant interaction C. a significant main effect for factor A (medication) and a significant interaction D. none of the above

The results of a repeated-measures ANOVA are reported as follows, F(3, 27)=1.12, p > .05. How many subjects participated in the study? a. 40 b. 36 c. 10 d. 9

C. 10

Which of the following is not part of the calculation of a two-factor ANOVA A. MS for A B. MS for AxB C. MS between treatments D. MS within treatments

C. MS between treatments

Tom wants to use a computer program to assess the reliability of his new intelligence test. The test has 10 items, and the computer program finds the average of all possible split-half correlations between groups of 5 items. What measure of reliability did he use?

Cronbach's alpha

A researcher uses an analysis of variance to test for mean differences among three treatment conditions using a sample of n = 8 different participants in each treatment (between subjects design). What degrees of freedom would the F-ratio from this analysis have? A. df = 23 B. df = 2, 23 C. df = 3, 21 D. df = 2, 21

A researcher uses an independent-measures t test to evaluate the mean difference between two treatments and obtains t(12) = 4.00. If the researcher had used an ANOVA to evaluate the data, what F-ratio would be obtained?

F(1, 12) = 16.00

The distribution of F-ratios is negatively skewed.

False

The result of a repeated-measures ANOVA stated that F(3, 21) = 4.57, p < .05. The study used a sample of n = 7 participants.

False

When using the Scheffé post hoc test for a repeated-measures ANOVA, the denominator for the F ratio should be _____.

MS Error

if the null is true for an analysis variance

MSbetween should be about the same size as MSwithin

Which of the following represents degrees of freedom for r?

N-2

Which of the following represents degrees of freedom for r? N - 2 N - 1 (N1 - 1)(N2 -1) Σ(X - Mx)2

N-2

when conducting a hypothesis test for the Pearson correlation coefficient, degrees of freedom is calculated by?

N-2

a _____ is a graphical representation of the relation between two variables?

NOT: correlation coefficient

Which of the following describes a typical distribution of F-ratios?

Positively skewed with all values greater than or equal to zero

A repeated-measures analysis of variance for a study comparing three treatment conditions with a sample of n = 10 participants, produces an F-ratio of F = 5.40. For this result, which of the following is the correct statistical decision?

Reject the null hypothesis with a = .05 but not with a = .01

In a two-factor ANOVA, which of the following is not computed directly but rather is found by subtraction?

SS(AxB)

In a two-factor ANOVA, which of the following is not computed directly but rather is found by subtraction?

SSAxB

In analysis of variance, what is measured by the MS values?

Sample Variance

Dr. Kang wants to know if there is a relationship between class attendance and class participation. Using the 30 students in her Intro to Psychology class, she finds a correlation of +0.35. Using a two-tailed test and a p level of 0.05, what should she conclude?

She should not reject the null hypothesis.

In an ANOVA, what is represented by the letter N?

The number of scores in the total research study

If a two-factor analysis of variance produces a statistically significant interaction, what can you conclude about the main effects?

The significance of the main effects is not related to the significance of the interaction

For an independent-measures ANOVA comparing four treatment conditions, dfbetween = 3.

True

For an independent-measures two-factor analysis of variance, all of the F-ratios use the same denominator.

True

If a two-factor study has 2 levels of factor A and 3 levels of factor B, then dfbet. treatments = 5.

True

If an analysis of variance produces SSbetween treatments = 30 and MSbetween treatments = 10, then the ANOVA is comparing four treatment conditions.

True

If the F-ratios for factor A and factor B both have df = 1, 36, then the F-ratio for the interaction will also have df = 1, 36.

True

If the F-ratios for factor A has df = 1, 36 and the F-ratio for the interaction has df = 2, 36, then the F-ratio for factor B will also have df = 2, 36.

True

In analysis of variance, large sample variances reduce the likelihood of rejecting the null hypothesis.

True

The F-ratio for a repeated-measures ANOVA has df = 1, 15. The research study used a total of n = 16 participants.

True

The F-ratio for a repeated-measures ANOVA has df = 2, 16. The research study compared 3 treatments with a sample of n = 8 participants.

True

Under what circumstances will the chi-square test for goodness of fit produce a large value for the chi-square statistic? When there is a large difference between the sample mean and the population mean. When the sample proportions are much different than the hypothesized population proportions. When the sample mean is close to the population mean. When the sample proportions match the hypothesized population proportions.

When the sample proportions are much different than the hypothesized population proportions.

A set of X and Y scores has MX = 4, SSX = 10, MY = 5, SSY = 40, and SP = 20. What is the regression equation for predicting Y from X? Yhat = 2X - 3 Yhat = 0.25X + 4 Yhat = 4X - 9 Yhat = 0.50X + 3

Yhat = 2X - 3 The slope b = SP/SSX = 20/10 = 2. The intercept a = MY - b*MX = 5 - 2*4 = -3. Hence, Yhat = 2X - 3

According to guidelines published by Cohen (1988), a correlation value of _____ is considered small, _____ is medium, and _____ is strong. a. 0.10; 0.30; 0.50 b. 0.25; 0.50; 0.75 c. 0.40; 0.60; 0.80 d. 1.00; 2.00; 3.00

a. 0.10; 0.30; 0.50

The Pearson correlation coefficient is symbolized by: a. r b. x c. c d. t

a. r

If there is a positive correlation between X and Y then the regression equation Yhat = bX + a will have _______. b < 0 b > 0 a > 0 a < 0

b > 0

In the first stage of a repeated-measures ANOVA, total degrees of freedom is partitioned into

between treatments df and within treatments df

Based on research with her patients, Dr. Sabine knows that the correlation coefficient between scores on an anxiety scale and comfort at a social gathering is -0.46. According to guidelines established by Cohen, how would the strength of this relationship be characterized? a. small b. medium c. large d. very large

c. large

The relation between a hockey player's age and the number of minutes he spent in the penalty box during the regular 2006-2007 season is shown in the figure. The 18 players were members of the New Jersey Devils hockey team who played in more than 40 games that season. Based on the scatterplot, what is the relation between a hockey player's age and the number of minutes he spent in the penalty box? a. perfect positive b. positive c. negative d. no relation

c. negative

What kind of correlation would one expect to find between the age of a car (nonclassic) and its value? a. positive b. zero c. negative d. perfect positive

c. negative

What kind of correlation would one expect to find between the severity of snowstorms and rates of attendance at college classes? a. positive b. zero c. negative d. perfect negative

c. negative

What is the research hypothesis when testing for significance using the Pearson correlation coefficient? a. μ 1 = μ2 b. r = 0 c. ρ≠0 d.ρ = 1

c. ρ≠0

the average of all possible split-half correlations is?

coefficient alpha, a measure of reliability

psychometricians are concerned with?

developing high-quality tests and measures

Which of the following is used to calculate the degrees of freedom for the AxB interaction in a two-way ANOVA? df(between-treatments) - df(A) - df(B) df(between-treatments) - df(within-treatments) df(A) - df(B) df(within-treatments) - (df(A) + df(B))

df(between-treatments) - df(A) - df(B)

In an analysis of variance, which of the following is determined by the size of the sample mean differences?

dfbetween

one assumption for using hypothesis testing for Pearson correlation is that one variable should vary equally at each level of the other variable. What is the easiest way to determine whether this assumption has been met?

draw a scatterplot to see whether the range of values is equal across all values of the other variable

which statement is an assumption that should be met before hypothesis testing with the correlation coefficient?

each variable should vary equally, regardless of the magnitude of the other variable

In the formula, Ŷ = a + b(X), a is the: observed value on the independent variable. slope. intercept. predicted value for the dependent variable.

intercept

The Pearson correlation coefficient can be used with:

interval or ratio data.

A reliable measure:

is consistent.

A measure is said to be valid if:

it measures what it is supposed to measure.

A measure is said to be valid if: its results are consistent. the specific procedures used in the measure are identified. it measures what it is supposed to measure. it is low in measurement error.

it measures what it is supposed to measure.

positively skewed

mean is higher than median/mode

A researcher wants to be able to predict first semester college grade point averages with as much accuracy as possible and so she would like to use both high school grade point averages and SAT scores as predictor variables. Which of the following techniques would be most appropriate to make this prediction? simple linear regression multiple regression proportionate reduction in error standardized regression coefficient

multiple regression

To predict a single dependent variable from more than one independent variable, which statistical technique would you use? structural equation modeling correlation simple linear regression multiple regression

multiple reression

What kind of correlation would you expect to find between the age of a home and its value?

negative

What kind of correlation would you expect to find between the age of a home and its value? perfect positive zero positive negative

negative

what kind of correlation would one expect to find between the age of a car (nonclassic) and its value?

negative

If the results from an intelligence test are different when given to the same person on two different occasions, then the test is:

not reliable.

what is the null hypothesis when testing for significance using the Pearson correlation coefficient?

p = 0

what is the research hypothesis when testing for significance using the Pearson correlation coefficient?

p =/ 0 (cross through equal sign)

What is the null hypothesis when testing for significance using the Pearson correlation coefficient? r =/ 0 ρ =/ 0 μ1 = μ2 ρ= 0

p=0

a technique that quantifies the degree of association between two variables after statistically removing the association of a third variable with both of those two variables is?

partial correlation

if one wishes to assess the relation between a farming county's average annual temperature and the crop yield, it may be important to take into account the overlapping variability that crop yield and temperature share with rainfall. to do so, one would compute a?

partial correlation

a researcher discovers that length of time spent following a Mediterranean diet is negatively correlated with risk of developing cancer. which statement logically follows from this information?

people who ate a Mediterranean diet for longer periods were less likely to have cancer

A positive correlation between hand size and foot size indicates that:

people with larger feet also tend to have larger hands.

a positive correlation between head size and foot size indicates that?

people with larger feet also tend to have larger heads

What kind of correlation would you expect to find between levels of family income and educational level?

positive

Regression is to ________ as correlation is to ________. relation; prediction causation; association prediction; relation association; causation

prediction; relation

The denominator of the Pearson correlation equation corrects for _____ and _____ issues present in the numerator.

sample size; variability

the denominator of the Pearson correlation equation corrects for _____ and _____ issues present in the numerator

sample size; variability

In analysis of variance, what is measured by the MS values?

sample variance

Before calculating the correlation coefficient, it is advisable to create a _____ as a way to display the association between the two variables.

scatterplot

In the equation for a regression line, the slope is: the value for X when Y is equal to 0. the amount that Y is predicted to increase for a 1-unit increase in X. the predicted value for Y when X is equal to 0. the z score of the amount that Y is predicted to increase as X increases.

the amount that Y is predicted to increase for a 1-unit increase in X.

"The incidence of depression among college students is negatively correlated with the number of sunny days each year in the locale where they attend college." This statement means that:

the chances of a college student being depressed tend to increase as there are fewer sunny days.

"The incidence of depression among college students is negatively correlated with the number of sunny days each year in the locale where they attend college." This statement means that: a student attending college in a locale with very few sunny days will become depressed. the chances of a college student being depressed tend to increase as there are fewer sunny days. the chances of a college student being depressed tend to increase as the number of sunny days increases. if a depressed student were to move to a locale with more sunny days, the student's depression would subside.

the chances of a college student being depressed tend to increase as there are fewer sunny days.

"the incidence of depression among college students is negatively correlated with the number of sunny days each year in the locale where they attend college." this statement means that?

the chances of a college student being depressed tend to increase with fewer sunny days

a negative correlation between a hockey player's age and the number of minutes he spends in the penalty box indicates that?

the older a player is, the less time he spends in the penalty box

A measure shows reliability when:

the same results are obtained each time it is used.

For ANOVA when the null is true, the F-ration is balanced so that the numerator and the denominator are both measuring the same sources of variance.

true

If a researcher expects that a new teaching technique will be more effective for children who are more than 10 years old than it is for younger children, then the researcher is predicting an interaction between the teaching technique and age.

true

In an analysis of variance produces SSbetween treatments = 30 and MSbetween treatments = 10, then the ANOVA is comparing four treatment conditions

true

In two-factor ANOVA, SSaxb is not computed directly but rather is found by subtraction

true

if a test actually measures what it is intended to measure, then that test is?

valid

the results of a study find a positive correlation between gum chewing and life expectancy. which statement would be a statistically appropriate response to the results of the study?

you become curious about what third variables might cause both increases in gum chewing and increases in life expectancy

what kind of correlation would one expect to find between the results of two dice thrown simultaneously?

zero

The distance between the Y value in the data and the Y value predicted from the regression equation is known as the residual. What is the value for the sum of the squared residuals? r2 (SSY) (1 - r2)(SSX) (1 - r2)(SSY) r2 (SSX)

(1 - r2)(SSY)

For the linear equation Y = 2X -3, which of the following points will not be on the line? (0, -3) (2, 1) (3, 0) (4, 5)

(3, 0) (If X is 3, then Y is 2X-3 = 2(3) - 3 = 6-3 = 3 (not 0).)

Which of the following values of the correlation coefficient indicates the weakest relationship between two variables?

+0.25

Which of the following values of the correlation coefficient indicates the weakest relationship between two variables? -0.32 +0.27 +0.25 -0.54

+0.25

what is the correlation between a person's weight as measured in grams and a person's weight as measured in pounds?

+1.00

measures of dispersion

- Describes the variability or spread of scores - Should be reported with mean - Range (Highest to lowest score) - Standard deviation (sd)

standard deviation

- Standard deviation (sd) (0 = same scores, larger the sd, the more the scores differ from mean) - Theoretical normal curve is divided into equal standards - The more normal a distribution of scores, the more this theoretical property applies 68.26% of scores fall within +1 to -1 standards

descriptive stats

- Summary information for each variable (Number of cases, Central tendency, Dispersion) - Used by researcher to describe variables - Used in statistical tests to analyze differences and relationships between variables

using descriptive stats

- methods section of research report (Mean, sd, range, and n should be reported for each variable) - Frequencies (f) (the number of times a particular value of a variable occurs) - Percentages (%) (often used to describe characteristics or attributes of participants)

normal (bell) curve

- theoretical distribution of scores - Majority of cases distributed around the peak in the middle - Progressively fewer cases moving away form the middle - Symmetrical (one side mirrors the other) - Mean, median, and mode have the same value

a correlation is computed using data from 30 people. what is the critical cutoff for a two-tailed hypothesis test with a p level of 0.05?

-0.361 and 0.361

a correlation is computed using data from 18 people. What is the critical cutoff for a two-tailed hypothesis test with a p level of 0.05?

-0.468 and 0.468

which of these values indicates the strongest relationship between two variables?

-0.72

Which of the following would indicate the STRONGEST relationship between two variables?

-0.83

Which of the following would indicate the strongest relationship between two variables? +0.81 -0.83 +0.04 -0.52

-0.83

which of these correlation coefficients allows a perfect prediction of scores on one variable from knowledge of scores on the other variable?

-1.00

which of these represents a perfect correlation?

-1.00 or 1.00

the numerical value for a correlation ranges between _____ and _____

-1.00; 1.00

According to guidelines published by Cohen (1988), a correlation value of ________ is considered small, ________ is medium, and _______ is strong.

0.10; 0.30; 0.50

An independent-measures research study compares three treatment conditions using a sample of n = 5 in each treatment. for this study, the three sample means are, M1 = 1, M2 = 2, M3 = 3. For ANOVA, what value would be obtained for SSbetween?

The following table shows the results of an analysis of variance comparing three treatment conditions with a sample of n = 7 participants in each treatment. Note that several values are missing in the table. What is the missing value for MSbeetween? Source SS df MS Between 20 xx xx F = xx Within xx xx 2 Total xx xx

How many separate groups of participants would be needed for an independent-measures, two-factor study with 3 levels of factor A and 4 levels of factor B? 12 7 3 4

12 (3 levels x 4 levels = 12 treatment groups. )

A researcher reports an F-ratio with df = 1, 24 for an independent-measures experiment. If all the treatments had the same number of participants, then how many individuals were in each treatment?

A researcher reports an F-ratio with df=1, 24 for an independent-measures experiment. If all the treatments had the same number of participants, then how many individuals were in each treatment?

A repeated-measures ANOVA produced an F-ration of F = 4.00 with df = 1, 14. If the same data were analyzed with a repeated-measures t test, what would be the df value for the t statistic?

A set of X and Y scores has SSX = 20, SSY = 10, and SP = 40. What is the slope for the regression equation?

2 That is, the regression slope b = SP/SSX = 40/20 = 2.

An analysis of variances produces df(total) = 29 and df(within) = 27. For this analysis, what is the df(between)?

2 29-27

A two-factor ANOVA produces a F-ratio factor A with df = 1, 36 and an F-ration for factor B with df = 2, 36. Which of the following describes the experiment producing these F-ratios?

2 levels of factor A and 3 levels of factor B df(rows) = # of rows - 1 df(column) = # od columns - 1

For a repeated-measures study comparing three treatment conditions with a sample of n=10 participants, what are the degrees of freedom for the repeated-measures F ratio? 2, 18 2, 9 3, 18 3, 9

2, 18 (Specifically, the df(between-treatments) = k-1 = 3-1 = 2, and the df(error) = df(within-treatments) - df(between-SUBJECTS) = (9+9+9) - (10-1) = 27 - 9 = 18.)

For a repeated-measures study comparing three treatment conditions with a sample of n=4 participants, what are the degrees of freedom for the repeated-measures F ratio? 2, 11 2, 9 2, 6 3, 11

2, 6 (Specifically, the df(between-treatments) = k-1 = 3-1 = 2, and the df(error) = df(within-treatments) - df(between-SUBJECTS) = (3+3+3) - (4-1) = 9 - 3 = 6. )

For the following data, what are the df values for the repeated-measures F-ratio? Treatments; Subject; I; II; III; P-totals; A; 3; 4; 5; 12; G = 27; B; 1; 1; 4; 6; SX2 = 109; C; 2; 1; 6; 9; T = 6; T = 6; T = 15; SS = 2; SS = 6; SS = 2

2,4

The following data represent the means for each treatment condition in a two-facto experiment. Note that one mean is not given. What value for the missing mean would result in no AxB interaction?

The following data represent the means for each treatment condition in a two-factor experiment. Note that one mean is not given. What value for the missing mean would result in no A´B interaction? B1; B2; A1; 20; 30; A2; 10; ?

A researcher reports an F-ratio with df = 2, 40 from a repeated-measures ANOVA. How many subjects participated in this experiment? 63 41 44 21

21 (we know from df(bt) = 2 that there were three treatment groups, so k = 3. We know that df(error) = (k-1)(n-1) as a rule. So, 40 = (3-1)(n-1), 40 = 2n-2, 42 = 2n, n = 21.)

1995 data from over 1,000 colleges published in U.S. News & World Report were used to predict the percent of alumni who donate to a college from the average SAT score of students attending that college. The resulting regression equation was Yˆ = -29.29 + 0.05(X). Using the regression equation what would you predict to be the percent of alumni who will donate to a college whose students' average SAT score is 1065? 0.02% 82.54% 0.08% 23.96%

23.96%

For an experiment involving 2 levels of factor A and 3 levels of factor B with a sample of n = 5 in each treatment condition, what is the value for dfwithin?

A researcher who is evaluating the significance of a multiple regression equation with two predictor variables obtains an F ratio with df = 2, 24. How many individuals were needed to produce the sample data used to find the regression equation?

27 For multiple regression equations with two predictor variables, dfresidual = n-3. As dfresidual is 24, n = 27.

A repeated-measures experiment compares three treatment conditions with a sample of n = 10 participants. If the data are analyzed with ANOVA, the analysis would have dftotal =

A repeated-measures study uses a sample of n = 15 participants to evaluate the mean differences among four treatment conditions. In the analysis of variance for this study, what is the value for dfbetween treatments?

A repeated-measures study uses a sample of n=15 participants to evaluate the mean differences among four treatment conditions. In the analysis of variance for this study, what is the value for df(between-treatments)? 14 59 4 3

A researcher reports an F-ratio with df = 2, 40 from a repeated-measures ANOVA. How many treatment conditions were compared in this experiment?

An analysis of variance produces SSbetween = 40 and MSbetween = 20. In this analysis, how many treatment conditions are being compared?

An analysis of variances produces dftotal = 29 and dfwithin = 27. For this analysis, how many treatment conditions are being compared?

The results of a two-factor analysis of variance produce df = 1, 30 for the F-ratio for factor A, and df = 2, 30 for the F-ratio for the AxB interaction. Based on this information, how many levels of factor B were compared in the study?

A sample of n=100 people is classified into four categories. If the results are evaluated with a chi-square test for goodness of fit, what is the df value for the chi-square statistic?

3 There are four categories (C = 4), and df = C-1, so df = 3. The sample size n=100 is not relevant.

An analysis of variances produces SS(between) = 40 and MS(between) = 20. In this analysis, how many treatment conditions are being compared?

3 df = 2

A researcher reports an F-ratio with df = 2, 18 from an independent-measures research study. Based on the df values, how many treatments were compared in the study, and what was the total number of subjects participating in the study?

3 treatments and 21 subjects

For an independent-measures ANOVA comparing three treatments with a sample of n = 5 in each treatment, what is the critical value for the F-ratio using a = .05?

3.88

For an independent-measures ANOVA comparing three treatments with a sample of n = 5 in each treatment, what is the critical value for the F-ratio using α = .05?

3.88

A repeated-measures analysis of variance produces SS(total) = 40 and SS(within-treatments) = 10. For this analysis, what is SS(between-treatments)? 30 400 Cannot be determined without additional information. 50

A two-factor study with two levels of factor A and three levels of factor B uses a separate group of n = 5 participants in each treatment condition. How many participants are needed for the entire study?

For a two-factor experiment with 2 levels of factor A and 3 levels of factor B and n = 10 subjects in each treatment condition, how many participants are in each level of factor A?

in two-factor study compares 2 levels of factor A and 3 levels of Factor B, with n = 5 in each treatment condition. how many participants for the entire study?

30 5*6

An ANOVA is used to evaluate the mean differences among three treatment conditions with a sample of n = 12 participants in each treatment. For this study, What is dfwithin treatments?

An ANOVA is used to evaluate the mean differences among three different treatment conditions with a sample of n = 12 participants in each treatment. For this study, what is the df(within treatments)?

33 k=3, n=12, N=36 df(within treatments) = N-k

An ANOVA is used to evaluate the mean differences among three different treatment conditions with a sample of n = 12 participants in each treatment. For this study, what is the df(total)?

35 k=3, n=12, N=36 df(total) = N-1

For an analysis of variance comparing four treatments, MSbetween = 12. What is the value of SSbetween?

For a two-factor study with 2 levels of factor A, 2 levels of factor B, and a separate sample of n=10 participants in each treatment condition, what is df(within-treatments)? 9 18 39 36

36 (Specifically, we know there are 2x2 = 4 treatment groups, x10 participants per group = 40 participants total. The value of df(within-treatments) is the sum of the df of each individual treatment group, so (10-1) * 4 = 9*4 = 36.)

The following table shows the results of a two-factor analysis of variance with 2 levels of factor A, 3 levels of factor B, and a separate sample of n = 5 participants in each of the treatment conditions. Note that several values are missing in the table. What is the missing value for the F-ratio for the AxB interaction? Source SS df MS Between 80 xx A 8 xx xx F= xx B xx xx 20 F= xx AxB xx xx xx F= xx Within xx xx xx Total 176 xx

The results of a repeated-measures ANOVA are reported as follows: F(3,27) = 1.12, p > 0.05. How many treatment groups were compared in the study? 27 4 28 3

A repeated-measures ANOVA produces SS(between-treatments) = 30 and MS(between-treatments) = 10. In this analysis, how many treatment conditions are being compared? 4 5 3 20

4 (SS(bt)/MS(bt) = df(bt) = 30/10 = 3, and the number of treatment conditions = df(bt)+1.)

For a repeated-measures study comparing three treatment conditions with a sample of n=4 participants, the participant totals (values of "P") are 3, 6, 9, and 6, and the SS values within each of the treatment groups are SS1 = 2, SS2 = 2, and SS3 = 6. What is the value of SS(error)? 6 10 4 2

4 (Specifically, SS(within-treatments) = 2+2+6 = 10. SS(between-SUBJECTS) = (sigma P^2)/k - (G^2/n) = 9/3 + 36/3 + 81/3 + 36/3 - 24^2/12 = 6. SS(error) = SS(within-treatments) - SS(between-SUBJECTS) = 10 - 6 = 4.)

For an experiment involving 3 levels of factor A and 3 levels of factor B, with a sample of n = 8 in each treatment condition, what are the df values for the F-ratio for the AxB interaction?

4, 63

with 3 levels for factor A and 3 levels for factor B, n = 8 in each treatment condition, what are the df values for the F-ration for the AxB interaction?

4, 63

For an experiment involving 3 levels of factor A and 3 levels of factor B, with a sample of n = 8 in each treatment condition, what are the df values of the F-ratio for the AxB interaction?

4, 63 df(A) = 3 - 1 = 2 df(B) = 3 - 1 = 2 df(AxB) = 2 * 2 = 4 df(within) = 9 * 7 = 63 = # of cells * (n-1)

For an experiment involving 3 levels of factor A and 3 levels of factor B, with a sample of n=8 in each treatment condition, what are the df values for the F-ratio for the AxB interaction? 6, 63 4, 63 2, 63 8, 63

4, 63 (Specifically, there are 9 treatment groups (3 levels of A x 3 levels of B), with n=8 each, so a total of 72 participants. df(within) = the sum of the df of each treatment group, so 9 x (8-1) = 63. df(between-treatments) = 9-1 = 8. df(A) = 3-1 = 2. df(B) = 3-1 = 2. df(AxB) = 8 - 2 - 2 = 4. Hence, the df(AxB) = 4, 63. )

A researcher reports an F-ratio with df = 2, 40 from a repeated-measures ANOVA. How many subjects participated in this experiment?

Ten years ago, only 15% of the U.S. population consisted of people more than 65 years old. A researcher plans to use a sample of n=300 people to determine whether the population distribution has changed during the past ten years. If a chi-square test is used to evaluate the data, what is the expected frequency for the older-than-65 category?

45 That is, one would expect 15% of the 300-person sample to be over 65 if the null hypothesis is true (i.e., if there had been no change in the demographics). 300 * 0.15 = 45.

An independent measures research study compares three treatment conditions using a sample if n = 5 in each treatment. For this study, the three samples have SS1 = 10, SS2 = 20, and SS3 = 15. What value would be obtained for MS(within)?

45/12

An independent-measures research study compares three treatment conditions using a sample of n = 5 in each treatment. for this study, the three samples have SS1 = 10, SS2 = 20, SS3 = 15. What value would be obtained for MSw/in?

45/12

A two-factor research study has 2 levels of factor A and three 3 of factor B with n = 8 participants in each treatment condition. For this study, what is the value for df(between treatments)?

The results of a two-factor analysis of variance produce df = 2, 36 for the F-ratio for factor A and df = 2, 36 for the F-ratio for factor B. How many participants are in each of the treatment conditions?

An analysis of variance produces SStotal = 80 and SSwithin = 30. For this analysis, what is SSbetween?

Data from the 1993 World Almanac and Book of Facts were used to predict the life expectancy for men in a country from the life expectancy of women in that country. The resulting regression equation was Yˆ = 9.32 + 0.79(X). Using the regression equation, what would you predict to be the life expectancy of men in a country whose life expectancy for women is 72 years? 64.64 years 47.56 years 79.36 years 66.20 years

66.20 years

A researcher obtains an F-ratio with df = 2, 12 in a repeated - measures study ANOVA. How many subjects participated in the study?

An analysis of variance produces dfbetween = 3 and dfw/n = 24. If each treatment has the same number of participants, then how many participants are in each treatment?

A chi-square test for independence has df = 3. What is the total number of categories (cells in the matrix) that were used to classify individuals in the sample?

8 The only way that df = 3 is if there are two rows and 4 columns (or 4 rows and 2 columns). You can draw those three "freely varying" cells in a row and then add one more row and one more column (because df = (R-1)*(C-1)). The matrix of 4x2 cells = 8 cells.

A repeated-measures ANOVA with n=5 subjects has df(within-treatment) = 12. What is the value for df(error) for this analysis? 48 16 Cannot determine df(error) without additional information. 8

8 ( df(error) = df(within-treatment) - df(between-SUBJECTS) = 12 - (5-1) = 8.)

The following table shows the results of a repeated-measures analysis of variance comparing two treatment conditions with a sample of n = 12 participants. Note that several values are missing in the table. What is the missing value for SStotal? Source; SS; df; MS; Between; xx; xx; 12; F = 4.00; Within; xx; xx; Bet. Sub.; 35; xx; Error; xx; xx; xx; Total; xx; xx

What is the implication when an ANOVA produces a very large value for the F-ratio?

A large F-ratio indicates the existence of a treatment effect because the differences between the treatments (numerator) are much bigger than the differences that would be expected if there were no effect (denominator)

Which of the following accurately reflects the relationship between reliability and validity?

A measure must be reliable for it to be valid, but a reliable measure is not necessarily valid

A two-factor research study is used to evaluate the effectiveness of a new blood-pressure medication. In this two-factor study, Factor A is medication versus no medication (2 levels) and Factor B is male versus female (2 levels). The medicine is expected to reduce blood pressure for both males and females, but is expected to have a much greater effect on males. What pattern of results should be obtained if the medication works as predicted? A significant main effect for factor A (medication) and a significant interaction. A significant interaction between factors A and B. A significant effect for factor A (medication). None of the other answers is correct.

A significant main effect for factor A (medication) and a significant interaction. (If the drug affects all sexes to some extent, that is evidence for a main effect of drug. If the drug affects one sex more than the other, that is evidence for an interaction between drug and sex. )

In a two-factor ANOVA, the F-ratios for factor A, factor B and the interaction of AxB ____. A. may have different df values but they all have the same denominator B. all have the same df values and they all have the same denominator C. may have different df values and may have different denominators D. all may have the same df values but they may have different denominators

A. may have different df values but they all have the same denominator

Which combination of factors will produce a large value for eta-squared in a single factor ANOVA? A. large mean differences and large sample variances B. large mean differences and small sample variances C. small mean differences and large sample variances D. small mean differences and small sample variance

An analysis of variance is used to evaluate the mean differences for a research study comparing four treatments with a separate sample of n = 5 in each treatment. If the data produce an F-ratio of F = 3.15, then which of the following is the correct statistical decision? A. reject the null hypothesis with alpha = .05 but not with alpha = .01 B. reject the null hypothesis with either alpha = .05 or alpha = .01 C. Fail to reject the null hypothesis with either alpha = .05 or alpha = .01 D. There is not enough information to make a statistical decision.

For an experiment involving two levels of factor A and 4 levels of factor B with a sample of n = 5 in each treatment condition (or cell), what is the value for df within? A. 23 B. 29 C. 32 D. 39

In a line graph showing the results from a two factor experiment, the levels of factor B are presented on the X-axis and, although the line for A1 is crooked, the points on the line are consistently 5 points higher than the line for A2. What result is indicated by this pattern? A. no indication of an interaction B. an indication of an overall A effect C. an indication of an A effect but no indication of an interaction D. an indication of an interaction but no indication of an A effect.

A repeated measures analysis of variance uses a sample of n = 5 individuals to evaluate the mean differences among three treatments. The ANOVA for this study has A. dfwithin treatments = 4 and dfbetween subjects = 4 B. dfwithin treatments = 14 and dfbetween subjects = 4 C. dfwithin treatments = 12 and dfbetween subjects = 4 D. dfwithin treatments = 12 and dfbetween subjects = 14

C (12, 4)

A two-factor ANOVA produces an F-ratio for factor A with df = 2, 36 and an F-ratio for factor B with df = 3, 36. Which of the following describes the experiment producing these F-ratios? A. 1 level of factor A and 2 levels of factor B B. 2 levels of factor A and 2 levels of factor B C. 3 levels of factor A and 4 levels of factor B D. 6 levels for both factors

C. 3 levels of factor A and 4 levels of factor B

For an experiment comparing more than two treatment conditions you should use analysis of variance rather than separate t tests because _____. A. separate t tests would require substantially more computations. B. a test based on variances is more sensitive than a test basd on means. C. conducing several t tests would inflate the risk of a Type I error. D. There is no difference between the two tests, you can use either one.

C. Conducting several t-tests would inflate the risk of a type I error

The results from a 2-factor ANOVA show a significant main effect for factor A and a significant main effect for factor B. Based on this information, you can conclude that A. there must be a significant interaction B. there probably is a significant interaction C. the interaction cannot be significant D. you cannot make any conclusion about the significance of the interaction

One assumption for using hypothesis testing for the Pearson correlation is that one variable should vary equally at each level of the other variable. What is the easiest way to determine if this assumption has been met?

Draw a scatterplot to see if the range of values is equal across all values of the other variables.

Abel and Kruger (2010) analyzed the smiles of professional baseball players listed in the Baseball Register. The photos of players were classified as either big smiles or no smiles. The age of death for all players were also recorded. The results revealed that players with big smiles lived longer than those with no smiles. Which statistic could be used to determine if there was a significant difference in life span between those with big versus no smiles? A. z for a single score B. z for a sample mean C. single sample t D. related samples t E. independent samples t

A researcher is conducting a chi-square test for independence to evaluate the relationship between gender and preference for three different designs for a new automobile. Each individual in a sample of n=30 males and n=30 females selects a favorite design from the three choices. If the researcher obtains a chi-square statistic of X2 = 4.81, what is the appropriate statistical decision for the test? Reject the null hypothesis with alpha = 0.05 but not with alpha = 0.01 Reject the null hypothesis with either alpha = 0.05 or alpha = 0.01 There is not enough information to determine the appropriate decision Fail to reject the null hypothesis with either alpha = 0.05 or alpha = 0.01

Fail to reject the null hypothesis with either alpha = 0.05 or alpha = 0.01 The matrix of choices for this chi-square test for independence has 2 genders x 3 car choices = six boxes. The degrees of freedom = (R-1)*(C-1) = (2-1)*(3-1) = 1*2 = 2. On the chi-square distribution table, for df=2, X2crit = 5.99 for alpha = 0.05 and 9.21 for alpha = 0.01. The X2 statistic obtained, 4.81, is smaller than these critical values. Hence, the null hypothesis cannot be rejected.

A new laundry detergent is supposed to be equally superior to the leading brand in both hot and cold water. If the new detergent works as predicted, then there should be an interaction between the brand of detergent and the temperature of the water.

False

A repeated-measures study has n = 8 participants and k = 3 treatments. For this study, dferror= 21.

False

A repeated-measures study uses a sample of n = 10 participants to evaluate the mean differences among three treatment conditions. For this study, dfbetween subjects = 18.

False

A repeated-measures t test produces a t statistic of t = 4.00 with df = 12. If the same data were evaluated with a repeated-measures ANOVA, the F-ratio would have df = 2, 12.

False

A research report presents the results of an independent-measures ANOVA as follows: F(3, 28) = 5.36, p < .01. If all the samples were the same size, then each sample had n = 7 participants.

False

A research report presents the results of an independent-measures ANOVA as follows: F(3, 28) = 5.36, p < .01. The research study compared three treatments.

False

A research report presents the results of an independent-measures ANOVA as follows: F(3, 28) = 5.36, p < .01. The research study used a total of 31 participants.

False

A researcher uses an independent-measures t test to evaluate the mean difference between two treatments. If the t statistic has df = 12, then an ANOVA evaluating the same data would produce an F-ratio with df = 1, 11.

False

A two-factor analysis of variance produces an F-ratio for factor A that has df = 3, 36. This analysis is comparing three different levels of factor A.

False

A two-factor analysis of variance with 2 levels of factor A and 3 levels of factor B involves six separate hypothesis tests.

False

A two-factor study compares 2 levels of factor A and 3 levels of factor B with a sample of n = 10 participants in each treatment condition. For this study, the F-ratio for factor A has df = 2, 54.

False

A two-factor study compares 2 levels of factor A and 3 levels of factor B with a sample of n = 5 participants in each treatment condition. This study uses a total of 25 participants.

False

A two-factor study compares 2 levels of factor A and 3 levels of factor B with a sample of n = 5 participants in each treatment condition. This study will use a total of 25 participants.

False

An ANOVA comparing two treatment conditions produces SSwithin = 80 and SSbetween = 50. For these data, h2 = 25/80.

False

Effect size for analysis of variance is measured by h2, which equals SSbetween divided by SSwithin.

False

For an analysis of variance comparing four treatment means with a separate sample of n = 8 participants in each treatment, the F-ratio will have df = 3, 31.

False

For an analysis of variance comparing three treatment means, H0 states that all three population means are the same and H1 states that all three population means are different.

False

For an independent-measures ANOVA with n = 10 participants in each treatment condition, dfwithin = 9.

False

For an independent-measures two-factor experiment, the bigger the values for the sample variances, the more likely it is that at least one of the F-ratios will be significant.

False

For the repeated-measures analysis, the F-ratio, on average, is expected to be zero when H0 is true.

False

If an analysis of variance produces SSbetween = 20 and SSwithin = 40, then h2 = 0.50.

False

If the F-ratio for factor A has df = 1, 40 and the F-ratio for factor B has df = 3, 40, then the F-ratio for the interaction must have df = 2, 40.

False

In an analysis of variance, MStotal = MSbetween + MSwithin.

False

Obtaining a significant interaction means that both factors A and B have significant main effects.

False

The following table shows the results of an analysis of variance comparing four treatment conditions with a sample of n = 5 participants in each treatment. Note that several values are missing in the table. What is the missing value for MSwithin? Source SS df MS Between 30 xx xx F = xx Within xx xx xx Total 62 xx

False

A researcher used a sample of n=60 individuals to determine whether there are any preferences among four brands of pizza. Each individual tastes all four brands and selects his/her favorite. If the data are evaluated with a chi-square test for goodness of fit using alpha = 0.05, then how large does the chi-square statistic need to be to reject the null hypothesis? Less than 79.08 Less than 7.81 Greater than 7.81 Greater than 79.08

Greater than 7.81 Because of the four brands of pizza (four categories C of response), the degrees of freedom df = C-1 = 4-1 = 3. The critical value for chi-square then can be read off of the distribution table.

The term "analysis: means separating or breaking a whole into parts. What is the basic analysis that takes place in analysis of variance?

In ANOVA, the total variability for a set of scores is separated into two components: between-treatments variability and within-treatments variability

If an analysis of variance is used for the following data, what would be the effect of changing the value of M2 to 25? Sample Data M1 = 10 M2 = 20 SS1 = 90 SS2 = 70

Increase SSbetween and increase the size of the F-ratio

If an analysis of variance is used for the following data, what would be the effect of changing the value of M2 to 20? what would be the effect of changing the value of SS1 to 50? Sample Data M1 = 10 M2 = 15 SS1 = 90 SS2 = 70

Increase SSbetween and increase the size of the F-ratio. Decrease SSwithin and increase the size of the F-ratio

If an analysis of variance is used for the following data, what would be the effect of changing the value of SS2 to 100? Sample Data M1 = 15 M2 = 25 SS1 = 90 SS2 = 70

Increase SSwithin and decrease the size of the F-ratio

Which of the following accurately describes the chi-square test for independence? It is similar to a correlation because it uses one sample to evaluate the relationship between two variables. It is similar to both a correlation and an independent-measures t test because it can be used to evaluate a relationship between two variables or a difference between two populations. It is similar to an independent-measures t test because it uses separate samples to evaluate the difference between separate populations. It is similar to a single-sample t test because it uses one sample to test a hypothesis about one population.

It is similar to both a correlation and an independent-measures t test because it can be used to evaluate a relationship between two variables or a difference between two populations.

If the mean and variance are computed for each sample in an independent-measures, two-factor experiment, which of the following types of sample data will tend to produce large F-ratios for the two-factor ANOVA?

Large differences between sample means and small sample variances

Which of the following is not used in an F-ratio for the two-factor analysis of variance? MS(B) MS(within-treatments) MS(A) MS(between-treatments)

MS(between-treatments)

What is the correct denominator for the repeated-measures F-ratio? MS(between-treatments) MS(between-subjects) MS(within-treatments) MS(error)

MS(error)

Which of the following is expected if the null hypothesis is true for an analysis of variance?

MS9between) should be about the same as MS(within)

Which of the following not used in an F-ratio for the 2-factor analysis of variance?

MSbetween treatments

What is the correct denominator for the repeated-measures F-ratio?

MSerror

Which of the following is not normally calculated as part of a one-way ANOVA? A. SStotal B. SSwithin C. MStotal D. MSwithin

MStotal

In an analysis of variance, which of the following is not true?

MStotal = MSbetween + MSSwithin

When using the Scheffe post hoc test for a repeated-measures ANOVA, the denominator for the F-ratio in the Scheffe test should be ________. MS(error) MS(within-treatments) MS(between-subjects) MS(between-treatments)

Ms(error)

On average, what is the value expected for the F-ratio if the null hypothesis is false?

Much greater than 1.00

On average, what value is expected for the F-ratio if the null hypothesis is false?

Much greater than 1.00

What is the principle reason why you should use ANOVA instead of several t tests to evaluate mean diffs when an experiment consists of 3 treatment conditions?

Multiple t tests accumulate the risk for a type 1 error

For the following data, what is SStotal? Treatments Subject I II III P-totals A 3 4 5 12 G = 27 B 1 1 4 6 SX2 = 109 C 2 1 6 9 T = 6 T = 6 T = 15 SS = 2 SS = 6 SS = 2

NOT 10

A coefficient alpha of _____ is considered a minimally acceptable level of reliability for measures that will be used in research studies in which individual scores will be averaged. a. 0.95 b. 0.90 c. 0.80 d. 0.75

NOT a. 0.95

a coefficient alpha of _____ is considered a minimally acceptable level of reliability for measures that will be used in research studies in which individual scores will be averaged

NOT: 0.90 or 0.95

based on research with her patients, Dr. Sabine knows that the correlation coefficient between scores on an anxiety scale and comfort at a social gathering is -0.46. according to guidelines established by Cohen, how would the strength of this relationship be characterized?

NOT: medium

if all the points on a scatterplot fall on a single line?

NOT: the relation between the variables is positive

the most widely used measure of reliability is?

NOT: the test-retest reliability

what is the relationship between correlation and causation?

NOT: there is no relationship between correlation and causation or correlation is both necessariy and sufficient

in a reanalysis of published studies, Twenge and Im (2007) found that for the time period of 1958 to 2001, the need for social approval of people in the United States was positively correlated with changes in the Dow Jones Industrial Average during that same period (the correlation coefficient was 0.10). this means that?

NOT: when the need for social approval was high, the Dow Jones Industrial Average was low

What is the null hypothesis when testing for significance using the Pearson correlation coefficient?

P=0

An analysis of variance is used to evaluate the mean differences for a research study comparing four treatments with a separate sample of n = 8 in each treatment. If the data produce an F-ratio of F = 5.50, then which of the following is the correct statistical decision?

Reject the null hypothesis with either α = .05 or α = .01.

In an analysis of variance, which of the following is determined by the size of the sample mean differences?

SSbetween

In an analysis of variance, which of the following determines the size of the variance in each of the individual samples?

SSwithin

For the regression equation Yhat = -2X + 6, what can be determined about the correlation between X and Y? The correlation definitely will be positive. The correlation definitely will be negative. The correlation will be relatively large and positive. The correlation will be relatively large and negative.

The correlation definitely will be negative.

In a repeated-measures analysis of variance (RMANOVA), how does the magnitude of the mean differences from one treatment to another contribute to the F-ratio? The mean differences add to the numerator of the F-ratio. The mean differences add to both the numerator and the denominator of the F-ratio. The sample mean differences do not influence the F-ratio. The mean differences add to the denominator of the F-ratio.

The mean differences add to the numerator of the F-ratio.

In a repeated-measures analysis of variance, how does the magnitude of the mean differences from one treatment to another contribute to the F-ratio?

The mean differences add to the numerator of the F-ratio.

In a two-facto experiment with 2 levels of factor A and 2 levels of factor B, three of the treatment means are essentially identical and one is substantially different from the others. What result(s) would be produced by this pattern of treatment means?

The pattern would produce main effects for both A and B, and an interaction

A researcher obtains a negative value for a chi-square statistic. What can you conclude because the value is negative? The observed frequencies are consistently larger than the expected frequencies (on average) The expected frequencies are consistently larger than the observed frequencies (on average) There are large differences between the observed and expected frequencies The researcher made a mistake. The value of chi-square cannot be negative.

The researcher made a mistake. The value of chi-square cannot be negative.

What is indicated by a large value for the chi-square statistic? The sample data (observed values) do not match the null hypothesis. There is a good fit between the sample data (observed values) and the null hypothesis. The observed values from the sample data are consistently larger than the expected values. The observed values from the sample data are consistently smaller than the expected values.

The sample data (observed values) do not match the null hypothesis.

In a two-factor ANOVA, what is the implication of a significant AxB interaction for the main effects? Neither of the two main effects can be significant. The significance of the interaction implies nothing about the significance of the main effects. At least one of the main effects also must be significant. Both of the main effects also must be significant.

The significance of the interaction implies nothing about the significance of the main effects.

If a two-factor analysis of variance produces a statistically significant interaction, what can you conclude about the main effects?

The significance of the main effect is not related to the significance of the interaction

In an ANOVA, what is represented by the letter T?

The sum of the scores in a specific treatment

For an ANVOA comparing three treatment conditions, what is stated by the null hypothesis?

There are no differences between any of the population means

For an ANOVA comparing three treatment conditions, what is stated by the null hypothesis (H0)?

There are no differences between any of the population means.

What is stated by the null hypothesis for the chi-square test for independence? Both variables have the same frequency distribution. The two variables have different frequency distributions. There is no relationship between the two variables. There is a relationship between the two variables.

There is no relationship between the two variables.

In an independent-measures ANOVA, individual differences contribute to the variance in the numerator and in the denominator of the F-ratio. For a repeated-measures ANOVA, what happens to the individual differences in the numerator of the F-ratio? None of the other options accurately describes individual differences in the numerator. Individual differences contribute to the variance in the numerator. They do not exist because the same individuals participate in all of the treatments. They are measured and subtracted out in the second stage of the analysis.

They do not exist because the same individuals participate in all of the treatments.

What is the relationship among the separate F-ratios in a two-factor ANOVA?

They may have different df values but they all have the same denominator.

What is the relationship among the separate F-rations in a two-factor ANOVA?

They may have different df values, but they all have the same denominator

What is the relationship among the three separate F-ratios in a two-factor ANOVA? They all have the same df values, but may have different denominators. They may have different df values, but they all have the same denominator. They may have different df values, and may have different denominators. They all have the same df values, and they all have the same denominator.

They may have different df values, but they all have the same denominator.

A repeated-measures study uses a sample of n = 8 participants to evaluate the mean differences between two treatment conditions. The analysis of variance for this study will have dferror = 7.

True

A two-factor study compares 2 levels of factor A and 2 levels of factor B with a sample of n = 20 participants in each treatment condition. If the results are evaluated with a two-factor ANOVA, all the F-ratios will have df = 1, 76.

True

A two-factor, independent-measures research study with 2 levels of factor A and 3 levels of factor B with n = 10 participants in each treatment condition would require a total of 60 participants.

True

An ANOVA is used to determine whether significant difference exist, and post test are used to determine exactly which treatment means are significantly different.

True

An ANOVA is used to determine whether significant difference exist, and post tests are used to determine exactly which treatment means are significantly different.

True

An F-ratio near 1.00 is an indication that the null hypothesis is likely to be true.

True

Because the repeated-measures ANOVA removes variance caused by individual differences, it usually is more likely to detect a treatment effect than the independent-measures ANOVA is.

True

F-ratios are always greater than or equal to zero.

True

For a repeated-measures study, dfbetween treatments= 3 and dftotal = 27. This means that there were n = 7 participants in the study.

True

For a two-factor analysis of variance, the significance of any specific F-ratio is completely independent of the significance of the other F-ratios.

True

For an ANOVA with SSbetween = 40 and SSwithin = 60, η2 = 40/100.

True

For an ANOVA, if SSbetween = 40 and SSwithin = 60, then h2 = 40/100.

True

For an ANOVA, when the null hypothesis is true, the F-ratio is balanced so that the numerator and the denominator are both measuring the same sources of variance.

True

For an analysis of variance comparing three treatment means with a separate sample of n = 10 participants in each treatment, dftotal = 29.

True

If the results of a two-factor ANOVA show no main effect for factor A and no significant interaction, then it is safe to conclude that factor A has no effect on the parfticipants' scores.

True

In the second stage of the repeated-measures ANOVA, individual differences are removed from the denominator of the F-ratio.

True

It often is possible to reduce the variance in an independent-measures design by using a participant variable such as age or gender as a second factor.

True

Post tests are only needed if H0 is rejected in an ANOVA comparing more than two treatments.

True

Post tests such as Scheff+ are not necessary for an analysis of variance comparing only two treatment conditions.

True

Post tests such as Scheffé are not necessary for an analysis of variance comparing only two treatment conditions.

True

SSwithin measures the size of the sample variances.

True

The analysis of total variability into between-treatments and within-treatments variability is the same for a repeated-measures ANOVA and an independent-measures ANOVA.

True

The larger the differences among the sample means, the larger the numerator of the F-ratio will be.

True

Whenever a two-factor experiment results in a significant interaction, you should be cautious about interpreting the main effects because an interaction can distort, conceal, or exaggerate the main effects of the individual factors.

True

When comparing more than two treatment means, why should you use an analysis of variance instead of using several t tests?

Using several t tests increases the risk of a Type I error.

Explain the difference between the testwise alpha level and the experimentwise alpha

When a single research study involves several hypothesis test, the testwise alpha level is the value selected for each individual test and the experimentwise alpha is the total risk of a Type 1 error that is accumulated doe all the separate tests

If there is no systematic treatment effect, then what is the expected, on average, for the F-ratio in an ANOVA?

When the null hypothesis is true, the expected value for the F-ratio is 1.00 because the top and bottom of the ratio are both measuring the same variance

in an investigation of the psychometric properties of the Criminal Sentiments Scale (CSS), Witte et al. (2006) administered the scale to 72 sex offenders. they found that scores on the scale correlated positively with recidivism for nonsexual crimes, but not for sexual crimes. This research suggests that the CSS is?

a valid measure of sentiment to commit nonsexual crimes, but not a valid measure of the sentiment to commit sexual crimes

Which of these correlation coefficients allows a perfect prediction of scores on one variable from knowledge of scores on the other variable? a. -1.00 b. 0 c. 0.50 d. 2.00

a. -1.00

When conducting a hypothesis test for the Pearson correlation coefficient, a researcher is testing the null hypothesis that the correlation value is: a. 0. b. 1.00. c. -1.00. d. either 1.00 or -1.00.

a. 0.

Why do correlation coefficients greater than 0.50 rarely occur in the social sciences? a. Human behavior is the product of many interacting variables; any single variable will be limited in its association with a behavior. b. Social scientists fail to construct experiments carefully enough to detect larger correlations. c. The highest value a correlation coefficient can take on is 0.60. d. Social scientists have not yet discovered the variables that are the best predictors of human behavior.

a. Human behavior is the product of many interacting variables; any single variable will be limited in its association with a behavior.

When a positive relation exists between two variables, what will be true in the calculation of the Pearson correlation coefficient? a. The product of most pairs of deviations will be positive. b. Most deviation scores will be positive. c. Most deviation scores will be negative. d. The product of most pairs of deviations will be negative.

a. The product of most pairs of deviations will be positive.

Test-retest reliability is determined by: a. administering the same measure to the same sample at two different points in time and calculating the correlation between an individual's performance on the two administrations. b. administering the same measure to two different samples at two different points in time and calculating the correlation between an individual's performance at the two different times. c. correlating the odd-numbered items of a measure with an individual's performance on the even-numbered items of that same measure. d. correlating the odd-numbered items of a measure with an individual's performance on the even-numbered items of a different measure.

a. administering the same measure to the same sample at two different points in time and calculating the correlation between an individual's performance on the two administrations.

What kind of correlation would one expect to find between levels of family income and household spending on consumer goods? a. positive b. zero c. negative d. perfect positive

a. positive

The denominator of the Pearson correlation equation corrects for _____ and _____ issues present in the numerator. a. sample size; variability b. sample size; nonnormality c. negative values; variability d. negative values; nonlinear data

a. sample size; variability

Before calculating the correlation coefficient, it is advisable to create a _____ as a way of displaying the association between the two variables. a. scatterplot b. line graph c. histogram d. polygon

a. scatterplot

The numerator (top half) of the Pearson correlation coefficient formula includes the: a. sum of the product of the deviations for each variable. b. square root of the product of the two sums of squares. c. difference between the two sample means. d. correction for variability and sample size.

a. sum of the product of the deviations for each variable.

"The incidence of depression among college students is negatively correlated with the number of sunny days each year in the locale where they attend college." This statement means that: a. the chances of a college student being depressed tend to increase with fewer sunny days. b. a student attending college in a locale with very few sunny days will become depressed. c. the chances of a college student being depressed tend to increase as the number of sunny days increases. d. a depressed student who moves to a locale with more sunny days will become less depressed.

a. the chances of a college student being depressed tend to increase with fewer sunny days.

Researchers who study the process of reading in children have discovered that better readers watch fewer hours of television. If a scatterplot of the data is drawn, the points on the graph would likely run from _____ left to _____ right. a. upper; lower b. lower; upper c. upper; upper d. lower; lower

a. upper; lower

test-retest reliability is determined by?

administering the same measure to the same sample at two different points in time and calculating the correlation between an individual's performance on the two administrations

researchers who study the process of reading in children have discovered that better readers make smoother eye movements across the page (i.e., there is a positive correlation between reading skill and the smoothness of the eye movements). Which statement is a possible cause of the correlation between smooth eye movements and reading ability?

all of these options are possible causes of the correlation

as the need for social approval increased, divorce rates decreased.

In a re-analysis of published studies, Twenge and Im (2007) found that for the time period of 1958 to 2001, the need for social approval of people in the United States was negatively correlated with the U.S. divorce rate during that same period (the correlation coefficient was -0.38). This means that: as the need for social approval increased, divorce rates decreased. the need for social approval prevents people from seeking divorce. as the need for social approval increased, divorce rates increased. the need for social approval spurs people to get divorced.

as the need for social approval increased, divorce rates decreased.

In a re-analysis of published studies, Twenge and Im (2007) found that, for the time period of 1958 to 2001, the need for social approval of people in the United States was negatively correlated with the U.S. divorce rate during that same period (the correlation coefficient was -0.38). This means that:

as the need for social approval increased, divorce rates decreased.

In a re-analysis of published studies, Twenge and Im (2007) found that, for the time period of 1958 to 2001, the need for social approval of people in the United States was positively correlated with changes in the Dow Jones Industrial Average during that same period (the correlation coefficient was +0.10). This means that:

as the need for social approval went up, the Dow Jones also increased.

in a reanalysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S. violent crime rate during the same period (the correlation coefficient was -0.31). This correlation means that?

as the need for social approval went up, the number of violent crimes decreased

In a re-analysis of published studies, Twenge and Im (2007) found that, for the time period of 1958 to 2001, the need for social approval of people in the United States was negatively correlated with the U.S. violent-crime rate during that same period (the correlation coefficient was -0.31). This means that:

as the need for social approval went up, the number of violent crimes decreased.

A correlation is computed using data from 18 people. What is the critical cutoff for a two-tailed hypothesis test with a p level of 0.05? a. -0.468 or 0.468 b. -0.468 and 0.468 c. -0.444 and 0.444 d. -0.444 or 0.444

b. -0.468 and 0.468

The numerical value for a correlation ranges between _____ and _____. a. 0; 1.00 b. -1.00; 1.00 c. -1.00; 0 d. negative infinity; positive infinity

b. -1.00; 1.00

A set of n = 5 pairs of X and Y scores has = 15, Y = 5, and Y = 10. For these data, the value of SP is a. 5 b. -5 c. 10 d. 25

b. -5

For a linear regression equation calculated for a sample of n = 25 pairs of X and Y values, what would be the df value for the standard error of estimate? a. 1 b. 23 c. 2 d. 6

b. 23

What is the relationship between correlation and causation? a. There is no relationship between correlation and causation. b. Correlation is necessary for causation. c. Correlation is sufficient for causation. d. Correlation is both necessary and sufficient for causation

b. Correlation is necessary for causation.

Based on research with her patients, Dr. Sabine knows that the correlation coefficient between scores on an anxiety scale and comfort at a social gathering is -0.35. If the critical value for r is 0.330, what should she conclude? a. The null hypothesis should be retained. b. Scores on the anxiety scale are significantly related to feelings of comfort in a social gathering. c. Scores on the anxiety scale are not significantly related to feelings of comfort in a social gathering. d. Scores on the anxiety scale are causally related to feelings of comfort in a social gathering.

b. Scores on the anxiety scale are significantly related to feelings of comfort in a social gathering.

In an investigation of the psychometric properties of the Criminal Sentiments Scale (CSS), Witte et al. (2006) administered the scale to 72 sex offenders. They found that scores on the scale correlated positively with recidivism for nonsexual crimes, but not for sexual crimes. This research suggests that the CSS is: a. a valid measure of sentiment to commit sexual crimes, but not a valid measure of the sentiment to commit nonsexual crimes. b. a valid measure of sentiment to commit nonsexual crimes, but not a valid measure of the sentiment to commit sexual crimes. c. a valid measure of both sentiment to commit nonsexual crimes and sexual crimes. d. not a reliable measure.

b. a valid measure of sentiment to commit nonsexual crimes, but not a valid measure of the sentiment to commit sexual crimes.

The average of all possible split-half correlations is: a. coefficient alpha, a measure of validity. b. coefficient alpha, a measure of reliability. c. the test-retest reliability. d. the test-retest validity.

b. coefficient alpha, a measure of reliability.

The most widely used measure of reliability is: a. the split-half correlation, in which the odd and even numbered items of a measure are correlated to assess internal consistency. b. coefficient alpha, the average of all possible split-half correlations. c. the test-retest reliability. d. criterion-related reliability.

b. coefficient alpha, the average of all possible split-half correlations.

If a negative relation exists between two variables, then low scores on one variable will be associated with _____ scores on the other variable. a. low b. high c. both high and low d. neither high nor low

b. high

Researchers who study the process of reading in children have discovered that better readers make smoother eye movements across the page. If a scatterplot of the data is drawn, the points on the graph would likely run from _____ left to _____ right. a. upper; lower b. lower; upper c. upper; upper d. lower; lower

b. lower; upper

According to guidelines published by Cohen (1988), a correlation value of 0.29 would be considered: a. small. b. medium. c. large. d. very large.

b. medium.

A technique that quantifies the degree of association between two variables after statistically removing the association of a third variable with both of those two variables is: a. split-half reliability. b. partial correlation. c. concurrent validity. d. coefficient alpha.

b. partial correlation.

If one wishes to assess the relation between a farming county's average annual temperature and the crop yield, it may be important to take into account the overlapping variability that crop yield and temperature share with rainfall. To do so, one would compute a: a. split-half reliability. b. partial correlation. c. concurrent validity. d. coefficient alpha.

b. partial correlation.

Nietfeld and Ender (2003) performed a study investigating the relation between the intelligence of student teachers and their efficacy in the classroom. This relation is depicted in the scatterplot, which shows fictional data that replicate the pattern of performance observed by the researchers. Based on the scatterplot, what kind of relation between intelligence and teaching efficacy did Nietfeld and Ender find? a. perfect positive b. positive c. negative d. no relation

b. positive

A _____ is a graphical representation of the relation between two variables. a. correlation coefficient b. scatterplot c. histogram d. polygon

b. scatterplot

The denominator (bottom half) of the Pearson correlation coefficient includes the: a. sum of the product of the deviations for each variable. b. square root of the product of the two sum of squares. c. difference between the sample means. d. square root of the deviations for each variable.

b. square root of the product of the two sum of squares.

If all the points on a scatterplot fall on a single line: a. there is no relation between the variables. b. the relation between the variables is perfect. c. the variables are causally related. d. the relation between the variables is positive.

b. the relation between the variables is perfect.

If a test actually measures what it is intended to measure, then that test is: a. reliable. b. valid. c. free of restriction of range problems. d. internally consistent.

b. valid.

What kind of correlation would one expect to find between the results of two dice thrown simultaneously? a. positive b. zero c. negative d. perfect positive

b. zero

Using the Pearson correlation coefficient to analyze the relationship between two variables is only appropriate if:

both variables are scale variables.

Which of the following Pearson correlations shows the greatest strength or consistency of relationship? a. +0.85 b. -0.33 c. -0.90 d. +0.74

c. -0.90

A coefficient alpha of _____ is considered a minimally acceptable level of reliability for measures that will be used to make decisions about individuals based on their scores on the measure. a. 0.65 b. 0.80 c. 0.90 d. 1.00

c. 0.90

For linear regression calculated for a sample of n = 20 pairs of X and Y values, what is the value for degrees of freedom for the predicted portion of the Y-score variance, MS regression? a. 18 b. 2 c. 1 d. 19

c. 1

A set of n = 10 pairs of scores has = 20, Y = 30, and Y = 74. What is the value of SP for these data? a. 24 b. 74 c. 14 d. -14

c. 14

A researcher who is evaluating the significance of a multiple regression equation with two predictor variables, obtains an F-ratio with df = 2, 18. How many individuals were needed to produce the sample data used to find the regression equation? a. 19 b. 20 c. 21 d. 18

c. 21

For linear regression calculated for a sample of n = 30 pairs of X and Y values, what is the value for degrees of freedom for the unpredicted portion of the Y-score variance, MS residual? a. 2 b. 1 c. 28 d. 29

c. 28

A Pearson correlation coefficient is calculated for 48 individuals. What value of df should be used to determine statistical significance in hypothesis testing? a. 48 b. 47 c. 46 d. 45

c. 46

A set of n = 15 pairs of scores ( X and Y values) has SS X = 4, SSY = 25, and SP = 6. The Pearson correlation for these data is a. 6/100 b. 6/(100/15) c. 6/10 d. 6/(10/v15)

c. 6/10

One assumption for using hypothesis testing for Pearson correlation is that one variable should vary equally at each level of the other variable. What is the easiest way to determine whether this assumption has been met? a. Review the value of r; if it is high, then the assumption has been met. b. Conduct a post hoc test following the calculation of r. c. Draw a scatterplot to see whether the range of values is equal across all values of the other variable. d. Calculate the cross-products of the deviation scores. If the result is positive, then the assumption has been met.

c. Draw a scatterplot to see whether the range of values is equal across all values of the other variable.

The correlation coefficient between class attendance and number of problems missed on an exam is (-0.77). Which statement regarding this finding is correct? a. If you start attending class more regularly, the number of problems you miss on the next exam is certain to be increased. b. There is no causal relationship between the two variables. c. If you attend class regularly, you are more likely to do well on the exam than someone who does not attend class regularly. d. The correlation demonstrates causality.

c. If you attend class regularly, you are more likely to do well on the exam than someone who does not attend class regularly.

A researcher discovers that length of time spent following a Mediterranean diet is negatively correlated with risk of developing cancer. Which statement logically follows from this information? a. Eating a Mediterranean diet increases the risk of developing cancer. b. Eating a Mediterranean diet reduces the risk of developing cancer. c. People who ate a Mediterranean diet for longer periods were less likely to have cancer. d. People who ate a Mediterranean diet for longer periods were more likely to have cancer.

c. People who ate a Mediterranean diet for longer periods were less likely to have cancer.

The results of a study find a positive correlation between gum chewing and life expectancy. Which statement would be a statistically appropriate response to the results of the study? a. You purchase a lifetime supply of gum because chewing gum is good for your health. b. You bemoan the possibility of living so long that you will have to chew lots of gum. c. You become curious about what third variables might cause both increases in gum chewing and increases in life expectancy. d. You tell all your friends and family members to chew gum because it is good for their health.

c. You become curious about what third variables might cause both increases in gum chewing and increases in life expectancy.

The Pearson correlation coefficient is a statistic that measures: a. the causal association between scale variables. b. an association between scale, ordinal, and nominal variables. c. a linear relation between two scale variables. d. relatedness in terms of variability between variables.

c. a linear relation between two scale variables.

The first step involved in calculating the Pearson correlation coefficient is to: a. multiply each raw score in one variable by the corresponding raw score in the second variable. b. square all the scores. c. calculate the deviation of each score from its mean. d. calculate the standard deviation for each variable.

c. calculate the deviation of each score from its mean.

According to guidelines published by Cohen (1988), a correlation value of -0.55 would be considered: a. small. b. medium. c. large. d. very large.

c. large.

A positive correlation between head size and foot size indicates that: a. having a large head causes a person to have large feet. b. having large feet causes a person to have a large head. c. people with larger feet also tend to have larger heads. d. people with larger feet tend to have smaller heads.

c. people with larger feet also tend to have larger heads.

A negative correlation between a hockey player's age and the number of minutes he spends in the penalty box indicates that: a. spending more time on the ice leads hockey players to become skilled at avoiding the referees. b. older players make fewer penalties because they have reduced testosterone levels. c. the older a player is, the less time he spends in the penalty box. d. an older player's greater experience has taught him how to avoid making penalties.

c. the older a player is, the less time he spends in the penalty box.

If one wishes to assess the relation between race and access to healthcare, it may be important to take into account the overlapping variability that race and access to healthcare share with household income. If a correlation between race and access to healthcare is found after controlling for household income, it indicates that: a. access to healthcare is not associated with race or household income. b. race, access to healthcare, and household income are perfectly correlated with one another. c. there are racial inequities in access to healthcare that cannot be accounted for by differences in household income. d. any differences in access to healthcare are attributable to differences in household income.

c. there are racial inequities in access to healthcare that cannot be accounted for by differences in household income.

In a reanalysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S. divorce rate during the same period (the correlation coefficient was -0.38). This correlation means that: a. the need for social approval prevented people from seeking divorce. b. the need for social approval spurred people to divorce. c. when the need for social approval was high, divorce rates were low. d. when the need for social approval was high, divorce rates were high.

c. when the need for social approval was high, divorce rates were low.

In a reanalysis of published studies, Twenge and Im (2007) found that for the time period of 1958 to 2001, the need for social approval of people in the United States was positively correlated with changes in the Dow Jones Industrial Average during that same period (the correlation coefficient was 0.10). This means that: a. the need for social approval caused people to invest more money in the stock market. b. the need for social approval prevented people from investing money in the stock market. c. when the need for social approval was high, the Dow Jones Industrial Average was also high. d. when the need for social approval was high, the Dow Jones Industrial Average was low.

c. when the need for social approval was high, the Dow Jones Industrial Average was also high.

Roman wanted to assess the internal consistency of his measure of happiness, so he measured reliability estimates by comparing items within his test. He reported a reliability estimate of +0.75. What measure of reliability is Roman using?

coefficient alpha

What is the correlation between a person's weight as measured in grams and a person's weight as measured in pounds? a. -1.00 b. 0.00 c. +0.50 d. +1.00

d. +1.00

A correlation is computed using data from 30 people. What is the critical cutoff for a two-tailed hypothesis test with a p level of 0.05? a. 0.306 b. 0.361 c. -0.306 and 0.306 d. -0.361 and 0.361

d. -0.361 and 0.361

Which of these values indicates the strongest relationship between two variables? a. 0.65 b. 0.59 c. -0.25 d. -0.72

d. -0.72

Which of these represents a perfect correlation? a. -1.00 only b. 1.00 only c. 0 d. -1.00 or 1.00

d. -1.00 or 1.00

A perfect linear relationship will yield a Pearson correlation value of: a. 1.00 only. b. 1.00 only. c. 0. d. 1.00 or 1.00.

d. 1.00 or 1.00.

Researchers who study the process of reading in children have discovered that better readers make smoother eye movements across the page (i.e., there is a positive correlation between reading skill and the smoothness of the eye movements). Which statement is a possible cause of the correlation between smooth eye movements and reading ability? a. The ability to make smooth eye movements improves reading ability. b. Having good reading skills allows a child to make smooth eye movements. c. Some third factor might cause both smooth eye movements and improved reading ability. d. All of these options are possible causes of the correlation.

d. All of these options are possible causes of the correlation.

Which statement is an assumption that should be met before hypothesis testing with the correlation coefficient? a. The two variables should be significantly related to one another. b. At least one of the variables is ordinal or nominal. c. The variability in one variable should not be the same as the variability in the other variable. d. Each variable should vary equally, regardless of the magnitude of the other variable.

d. Each variable should vary equally, regardless of the magnitude of the other variable.

When conducting a hypothesis test for the Pearson correlation coefficient, degrees of freedom is calculated by: a. Σ(X - MX)2. b. (N1 - 1)(N2 - 1). c. N - 1. d. N - 2.

d. N - 2.

Which of these is NOT an assumption when conducting hypothesis testing for r? a. The population distributions should be normal. b. To insure generalizability, the data should be randomly selected. c. The variability of scores on one variable should be equal across all levels of the second variable. d. The variables being studied are positively correlated.

d. The variables being studied are positively correlated.

In a reanalysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S. violent crime rate during the same period (the correlation coefficient was -0.31). This correlation means that: a. the need for social approval prevented people from committing violent crimes. b. the need for social approval spurred people to commit violent crimes. c. as the need for social approval went up, the number of violent crimes also increased. d. as the need for social approval went up, the number of violent crimes decreased.

d. as the need for social approval went up, the number of violent crimes decreased.

A linear regression equation is computed for a sample of n = 18 pairs of X and Y scores. For the analysis of regression testing the significance of the equation what are the df values for the F-ratio? a. df = 1, 16 b. df = 2, 15 c. df = 2, 16 d. df = 1, 17

d. df = 1, 17 WRONG a. df = 1, 16

Using the Pearson correlation coefficient to analyze the relationship between two variables is only appropriate if the variables are: a. scale variables. b. ordinal variables. c. linearly related. d. linearly related and scale variables.

d. linearly related and scale variables.

The scatterplot, created from 1995 U.S. News & World Report data on approximately 1,300 U.S. colleges and universities, depicts the relation between the student-faculty ratio at the school and the number of admissions applications the school received. Based on the scatterplot, what is the relation between an institution's student-faculty ratio and the number of applications it receives? a. perfect positive b. positive c. negative d. no relation

d. no relation

A set of n = 20 pairs of scores produces a Pearson correlation of r = 0.40 with SSY = 100. What is the standard error of estimate for the regression equation? a. v84/1 b. v16/1 c. v16/18 d. v84/18

d. v84/18

What is the null hypothesis when testing for significance using the Pearson correlation coefficient? a. μ1 = μ2 b. r = 0 c. r≠0 d. ρ = 0

d. ρ = 0

A linear regression equation is computed for a sample of n=13 pairs of X and Y scores. For the analysis of regression testing the significance of the equation, what are the df values for the F ratio? df = 1, 11 df = 2, 11 df = 2, 10 df = 1, 12

df = 1, 11 (The numerator df for a linear regression with a single predictor variable is always 1. The denominator df for such a regression is n-2, or 11.)

An analysis of regression is used to test the significance of a linear regression equation based on a sample of n=20 individuals. What are the df values for the F ratio? df = 2, 18 df = 1, 19 df = 2, 19 df = 1, 18

df = 1, 18

A researcher uses analysis of variance to test for mean differences among three different treatments with a sample of n = 12 in each treatment. The F-ratio for this analysis would have what df values?

df = 2, 33 df(w) = N-k df(b) = k-1 k=3, n=12, N=36

In analysis of variance, w/ 3 treatments and sample of n = 12

df = 2,35

In analysis of variance, each independent variable is referred to as a ___________. stage. level. factor. comparison.

factor

A new laundy detergent is supposed to be equally superior to the leading brand in both hot and cold water. if the new detergent works as predicted, then there should be an interaction between the brand of detergent and the temp. of water

false

Effect size for analysis of variance is measured by η^2 which equals SSbetween divided by SSwithin

false

For an independent-measures two factor experiment, the bigger the values for the sample variances, the more likely it is that at least one of the F-ratios will be significant

false

If the F-ratio for factor A has a df = 1,40 and the F-ratio for factor B has a df = 3,40. the interaction F-ration will have a df = 2,40

false

Independent-measures ANOVA; F(3,28) = 5.36, p < .01. did the research compare 3 treatments?

false

a 2-factor independent-measures research study with 2 levels of factor A and 2 levels of Factor B would require 2 separate groups of participants

false

in two-factor study compares 2 levels of factor A and 3 levels of Factor B, with n = 10 in each treatment condition. F-ration for factor A has df = 2, 54

false

why do correlation coefficients greater than 0.50 rarely occur in the social sciences?

human behavior is the product of many interacting variables; any single variable will be limited in its association with a behavior

For a fixed level of significance, the critical value for chi-square will _________________. increase as the sample size increases increase as the df value increases decrease as the df value increases decrease as the sample size increases

increase as the df value increases

using the Pearson correlation coefficient to analyze the relationship between two variables is only appropriate if the variables are?

linearly related and scale variables

Using the Pearson correlation coefficient to analyze the relationship between two variables is only appropriate if the variables are?

linearly related and scaled variable

what is the formula for the Pearson correlation coefficient?

look up

researchers who study the process of reading in children have discovered that better readers make smoother eye movements across the page. if a scatterplot of the data is drawn, the points on the graph would likely run from _____ left to _____ right

lower; upper

negatively skewed

mean is lower than median/mode

according to guidelines published by Cohen (1988), a correlation value of 0.29 would be considered?

medium

The regression line is the line that: is the mean of our dependent variable. minimizes the correlation coefficient. minimizes our error in predicting scores on the dependent variable. minimizes our error in predicting scores on the independent variable.

minimizes our error in predicting scores on the dependent variable.

What kind of correlation would you expect to find between the severity of snowstorms and rates of attendance at college classes?

negative

What kind of correlation would you expect to find between the severity of snowstorms and rates of attendance at college classes? positive negative zero perfect negative

negative

what kind of correlation would one expect to find between the severity of snowstorms and rates of attendance at college classes?

negative

Y is the symbol for a(n) ________ and Ŷ is the symbol for a(n) ________. observed score; predicted score score on the dependent variable; score on the independent variable predicted score; observed score score on the independent variable; score on the dependent variable

observed score; predicted score

The following scatterplot depicts fictional data that replicate the pattern of performance observed by Nietfeld and Ender (2003). Figure: Teaching Efficacy. Nietfeld and Ender (2003) performed a study investigating the relation between the intelligence of student teachers and their efficacy in the classroom. This relation is depicted in the scatterplot. Based on this scatterplot, what kind of relation did they find between intelligence and teaching efficacy?

positive

Which of the following accurately describes the chi-square distribution? symmetrical with a mean of zero symmetrical with a mean equal to n-1 positively skewed with all values greater than or equal to zero negatively skewed with all values greater than or equal to zero

positively skewed with all values greater than or equal to zero

Simple linear regression allows us to: determine the relation among four or more variables. infer the direction of causal relations. predict an individual's score on the dependent variable from their score on the independent variable. predict an individual's score on a dependent variable from their score on multiple independent variables.

predict an individual's score on the dependent variable from their score on the independent variable.

The branch of social science that specializes in the development of tests and measures is called:

psychometrics.

the Pearson correlation coefficient is symbolized by?

r (in italics)

For which of the following correlations would the data points be most widely scattered around the regression line? r = -0.80 r = 0.50 r = 0.10 There is no relationship between the correlation and how close the data points are to the regression line.

r = 0.10 Values of r closer to zero imply more sparsely scattered points; the sign (positive or negative) is not relevant in this case.

before calculating the correlation coefficient, it is advisable to create a _____ as a way of displaying the association between the two variables

scatterplot

based on research with her patients, Dr. Sabine knows that the correlation coefficient between scores on an anxiety scale and comfort at a social gathering is -0.35. If the critical value for r is 0.330, what should she conclude?

scores on the anxiety scale are significantly related to the feelings of comfort in a social gathering

In the formula, Ŷ = a + b(X), b is the: intercept. slope. predicted value for the dependent variable. observed value on the independent variable.

slope

The standardized regression coefficient expresses a predicted change in the dependent variable in terms of: error units. standard deviations units. a 1-unit change in the independent variable. slope.

standard deviation units

An important point to remember about correlation is that while there is a _______________ relationship, correlation does not equal____________.

statistical; causation

An important point to remember about correlation is that while there is a _______________ relationship, correlation does not equal____________. statistical; causation factual; causation probable; causation plausible; causation

statistical; causation

A researcher uses an ANOVA to evaluate the mean difference between two treatments and obtains F(1, 22) = 4.00. If the researcher had used an independent-measures t test to evaluate the data, what t value would be obtained?

t (22) = 2.00

Tara wanted to assess the reliability of her measure of happiness, so she had a group of introductory psychology students complete the measure of happiness two times and then compared the scores, calculating a correlation coefficient. What method did Tara use to assess reliability?

test-retest

Two variables are said to interact when ____.

the effect of one independent variable depends on the levels of the second variable

two variables are said to interact when

the effect of one independent variable depends on the levels of the second variable

Two variables are said to interact when _____________. both variables produce a change in the subjects' scores. the effect of one independent variable depends on the levels of the second variable. both variables are equally influenced by a third factor. the two variables are differentially affected by a third variable.

the effect of one independent variable depends on the levels of the second variable.

In a two-factor analysis of variance, a main effect is defined as _________. the difference between the largest treatment mean and the smallest treatment mean. the mean difference between the two factors. the mean differences among the levels of one factor. the mean differences among all treatment conditions.

the mean differences among the levels of one factor.

A negative correlation between a hockey player's age and the number of minutes he spends in the penalty box indicates that:

the older a player is, the less time he spends in the penalty box.

A negative correlation between a hockey player's age and the number of minutes he spends in the penalty box indicates that: the older a player is, the less time he spends in the penalty box. older players make fewer penalties because they have reduced testosterone levels. an older player's greater experience has taught him how to avoid making penalties. spending more time on the ice leads hockey players to become skilled at avoiding the referees.

the older a player is, the less time he spends in the penalty box.

In the equation for a regression line, the intercept is: the value for X when Y is equal to 0. the z score of the amount that Y is predicted to increase as X increases. the amount that Y is predicted to increase for a 1-unit increase in X. the predicted value for Y when X is equal to 0.

the predicted value for Y when X is equal to 0.

when a positive relation exists between two variables, what will be true in the calculation of the Pearson correlation coefficient?

the product of most pairs of deviations will be positive

If all the points on a scatterplot fall on a single line:

the relation between the variables is perfect.

If all the points on a scatterplot fall on a single line: the relation between the variables is perfect. there is no relation between the variables. the variables are causally related. there is a positive correlation between the two variables.

the relation between the variables is perfect.

The denominator of the Pearson correlation coefficient includes:

the square root of the product of the two sum of squares.

The numerator of the Pearson correlation coefficient formula includes:

the sum of the product of the deviations for each variable.

A Pearson correlation coefficient is calculated for 48 individuals. What value of df should be used to determine statistical significance in hypothesis testing?

the variables are linearly related.

The Pearson correlation coefficient is only appropriate when:

the variables are linearly related.

why would you not do posttests if the decision from the ANOVA was to fail to reject the null hypothesis

there are no significant differences to test for

if one wishes to assess the relation between race and access to healthcare, it may be important to take into account the overlapping variability that race and access to healthcare share with household income. if a correlation between race and access to healthcare is found after controlling for household income, it indicates that?

there are racial inequities in access to healthcare that cannot be accounted for by differences in household income

What is the relationship amoung the seperate F-rations in a 2-factor ANOVA

they may have different df values but they all have the same denominator

Partial correlation allows for the control of _________ variables.

third

Partial correlation allows for the control of _________ variables. weakly related independent dependent third

third

What is the purpose of posttests?

to determine exacty which treatment condition are significantly different.

What is the purpose for post tests?

to determine which treatments are significantly different.

A 2-factor study compares three different treatment conditions (factor 1) for males and females (factor 2). in this study, the main effect for gender is determined by the over all mean score for the males (averaged over the three treatments) and the corresponding overall mean score for the females.

true

For an ANOVA with SSbetween = 40 and SSw/n = 60, η^2 = 40/100

true

For an independent-measures two-factor experiment, the bigger the differences b/ween the sample means, the more likely it is that one of the F-ratios is significant

true

Post tests are only needed if H0 is rejected in an ANOVA comparing more than 2 treatments

true

SSbetween measures the size of the mean differences from one treatment to another

true

if a 2-factor study has 2 levels of factor A and 3 levels for Factor B then the df.b/ween treatments = 5

true

For an independent-measures two factor experiment, with 2 levels of Factor A and 3 levels for factor B with n = 10 participants in each treatment condition would require a total of 60 participants. if the same study had n = 5, than their would be 25 participants

true false

researchers who study the process of reading in children have discovered that better readers watch fewer hours of television. If a scatterplot of the data is drawn, the points on the graph would likely run from _____ left to _____ right

upper; lower

If we believe we are creating a measure of loneliness but in fact it measures introversion, we would say that our measure lacks:

validity.

in a reanalysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S. divorce rate during the same period (the correlation coefficient was -0.38). this correlation means that?

when the need for social approval was high, divorce rates were low

when the need for social approval was high, the Dow Jones Industrial Average was also high

explain why you would no do post tests if the analysis is comparing only 2 treatments

you already know which treatments would be different

The results from a 2-factor analysis of variance shows a significant main effect for factor A, as well as for Factor B, What can you conclude about the main effects?

you cannot make any conclusion about the significance of the interaction

What is the formula for the Pearson correlation coefficient?

Σ[(X-Mx)(Y-My)]/√(SSx)(SSy)

What is the null hypothesis when testing for significance using the Pearson correlation coefficient?

Descriptive statistics, Statistics 2022

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