Psych Unit 3
How many F statistics are calculated in a two-way between-groups ANOVA?
3
A behavioral researcher reports the results of an interaction in a two-way between-groups ANOVA as F(1,84) = 3.53. What decision should be made based on the value of this test statistic?
Fail to reject the null hypothesis and conclude there is no support for a combined effect of the variables.
A researcher reports the results of an ANOVA for a repeated-measures design as "F(2, 12) = 7.85, p<.01" This study used a sample of n = 13 participants.
False
Lou examined tolerance to four different psychoactive drugs among different groups of rats. He found a significant difference between groups and wishes to report an effect size for his study. Lou asks for your advice on whether to report R^2 or w^2 for his data. What would you advise?
He should report w^2 , as it is a less biased measure of effect size than R^2
Justin is examining the effectiveness of using scare tactics to manipulate the behaviors of 54 people living in different regions of the same island, categorized as the beach, the valley, and the mountains. What is the first step Justin should follow for hypothesis testing?
Identify population 1 as all beach inhabitants on the island, population 2 as all valley inhabitants on the island, and population 3 as all mountain inhabitants on the island. He should also use an F distribution with a one-way between-groups ANOVA
Vincent scored 83 on his statistics midterm and the class average was 86. What would his deviation and z score be in a distribution of midterm grades?
It would be negative
In a research report, which section includes information about the determination of the study's sample size?
Methods
How are degrees of freedom calculated for the r distribution?
N-2
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
The strength of a correlation coefficient is independent of its sign
True
Validity is difficult to assess and is sometimes not considered as a result.
True
When examining adjusted standardized residuals following a chi-square analysis, what minimum calculated value indicates the cell's observed frequency is different from its expected frequency?
2.0
Matched Groups
- Matched groups use different people who are similar on all of the variables that we want to control - We can analyze our data as if the same people are in each group, giving us additional statistical power.
For the data in the ANOVA source table, what is the effect size?
0.45
The campus testing service is conducting a study to determine the relation between method of presentation (standard lecture versus computer presentation) and type of lecture (psychology, economics, or statistics) to lecture comprehension. How would we describe this design?
2x3 between-groups ANOVA
A Tukey HSD is computed to compare two groups following an ANOVA that compared five groups. The within-groups degrees of freedom for the test are 15, and the computed HSD value is 5.24. What could we conclude about this analysis if we evaluated it at a p level of 0.05?
The test statistic is significant, revealing a statistical difference between the two groups
For the within groups ANOVA, SSwithin groups = SSsubjects + SSerror
True
It is advantageous to use a within-groups ANOVA compared to a between-groups ANOVA because with a within-groups ANOVA:
We have a reduced error because the same participants contribute to each condition of the study.
A test that is conducted when there are multiple groups of scores, but specific comparisons have been chosen prior to data collection is called
a planned comparison
When drawing a line of best fit, it is "best" to use ________ point(s) of ________ values.
at least 2; low and high
The news reports that the relative risk for contracting a deadly new disease is increased 49% if you are left-handed. Being a lefty yourself, what should you check first before becoming alarmed?
base rate of occurrence of the disease in the general population
Some people are "cat people" and others are "dog people" - but which are more prevalent in Alex's research methods class? What statistical test could help Alex evaluate this question and the data she would likely collect?
chi-square test for goodness of fit
To graph the results of a chi-square test, you need to calculate:
conditional proportions
Which of the following formulas for the degrees of freedom in a between-groups ANOVA is correct?
dfbetween = Ngroups - 1
What is the primary limitation of the correlation coefficient?
it cannot be used to establish causal relations between two variables
If social anxiety is negatively correlated with the number of friendships a person has, which statement regarding the line of best fit, or regression line, would be true?
the line will start in upper left corner of the graph and end in the lower-right corner.
When computing our chi-square statistic, we calculate the difference between what two values?
the observed and the expected frequency
To compute a less biased measure of effect size with a one-way between-groups ANOVA, we calculate:
w^2
When graphing a correlation coefficient, how many data points come from each participant?
1 data point
IF the population distributions are slightly skewed
ANOVA can be used because F is robust
Which of the following is considered one of the "new statistics" to be included in the Results section of a research report, and which APA now requires of researchers submitting papers for publication?
Confidence interval
In a two-way ANOVA, three _______ statistics are calculated.
F
Which distribution allows various types of statistical analyses to be made and is the most complex?
F
When working with one nominal variable with three levels, a chi-square test for independence would be used.
False
When using a one-way within-groups ANOVA, the variability due to individual differences in reduced, resulting in a ________ F statistic and making it _______ to reject the null hypothesis.
Larger; easier
A psychology professor wishes to see if students' intended college major influences their performance in an Introductory Psychology class. At the end of the semester, the professor examines the grades of four different groups of students: psychology majors, business majors, pre-med students, and pre-nursing students. Which statistical test should the professor use to analyze these data?
One-way between-groups ANOVA
A psychology advisor wishes to see if students' grade point averages are related to their GRE scores when they apply to graduate school. To investigate this question, the advisor should us a:
Pearson correlation
A psychology advisor wishes to see if students' grade point averages are related to their GRE scores when they apply to graduate school. To investigate this question, the advisor should use a:
Pearson correlation
A psychology professor wishes to see if students' attendance over the course of the semester is related to their grades on the final exam. To investigate this question, the professor should use a:
Pearson correlation
A researcher in I/O psychology investigates the impact of color and lighting on mood at work. She manipulates the paint used in offices, including the presentation of four different colors. She also manipulates lighting by using three different lighting conditions. The null hypothesis for the interaction in this study would be:
The effect of office color is not dependent on the type of lighting condition
Which statement is NOT an assumption of ANOVA?
The samples should be from a population with a known mean and standard deviation.
Which statement best describes an interaction in a two-way ANOVA?
The two independent variables have a combined effect on the dependent variable that is not present with either independent variable alone
When using a one-way within-groups ANOVA, the variability due to individual differences is reduced, resulting in a ________ F statistic and making it _________ to reject the null hypothesis.
larger; easier
_______________________ refers to the tendency of scores that are particularly high or low to drift towards the mean over time.
regression to the mean
After a researcher __________ the null hypothesis, the researcher should conduct a(n) __________ to determine which means are statistically significantly different from each other.
rejects; post hoc test
Nonparametric tests differ from parametric tests in that they are:
statistical tests that are not based on a set of assumptions about the population
When a researcher correlates scores on a newly developed instrument with scores from an existing test, the researcher is attempting to establish the instrument's:
validity
A repeated measures analysis of variance produces SStotal = 40 and SSerror = 10. For this analysis, what is SSbetween?
Cannot be determined from the information given
Following a one-way within-groups analysis of variance that results in a significant F statistic, the researcher should:
Conduct post hoc tests to determine where the significant differences between levels of the independent variable exist.
The standardized regression coefficient (B) for each variable in a multiple regression equation is equivalent to that variable's correlation (r) with the dependent variable.
False
A researcher for a computer gaming company is interested in visual accuracy among video game players. The indicators of visual accuracy are gaming ability (high average scores versus low average scores) and a computer "flicker" program that indicates changes in either the central or the noncentral region of a scene. The dependent variable is the time it takes to notice a change during flickers. When the researcher looks at a table of means, the data show that central flicker and high gaming ability = 40; noncentral flicker and high gaming ability = 20; central flicker and low gaming ability = 20; and noncentral flicker and low gaming ability = 40. Assuming a very powerful statistical test, the researcher should find:
No main effects
The Open Science Framework has developed different badges to recognize ethical and transparent practices. Which badge indicates that the researchers have made their experimental resources and materials available to anyone wishing to conduct their own analyses?
Open Material
A psychology professor wishes to determine if the type font on lecture slides impacts student learning. To test this question, the professor uses the Comic Sans font for one week's lecture and then uses the Helvetica font the next week; she examines students' quiz performance at the end of each week of class. The psychology professor should use a(n) _________ to analyze the data.
Paired-samples t test
A researcher is examining the relation between store location (more affluent versus less affluent neighborhoods) and type of store (coffeehouse, doughnut shop, or fast-food restaurant) on sales of coffee. The researcher finds that more coffee is sold in coffeehouses in the upper-class neighborhood, whereas fast-food restaurants sold more coffee in the middle-class neighborhood. What type of effect is this?
Qualitative interaction
An advantage of the one-way within-groups ANOVA is that researchers can:
Reduce within-groups variability by having the same participants in each group
A psychology advisor wishes to see if students' grade point averages are predictive of the students' GRE scores when they apply to graduate school. To investigate this question, the advisor should use a:
Regression
What statistical test should a researcher use if the researcher is determining if one scale variable predicts a second scale variable?
Regression
James thinks his new tutoring method, "statistics 360," is highly effective compared to commercially available methods. He selects the worst students in his statistics class and tries his new tutoring strategy. Which statement describes a threat to the validity of his hypothesis even if the students do very well after the tutoring sessions?
Regression to the mean is likely to occur
__________ is a useful statistical analysis for predicting behavior, and ___________ is a useful technique for finding the direction and strength of a relation between two variables
Regression; correlation
Gretchen is comparing verbal ability scores for four groups. She finds that the F statistic for her test is 4.01, and the cutoff value she identified prior to her analysis was 3.45. Should Gretchen reject or fail to reject the null hypothesis and what, if any, other steps does she need to take?
Reject the null hypothesis since her F statistic is beyond the cutoff, and perform a post hoc test to determine between which groups the significant difference occurs
The use of WEIRD samples in psychological research has led some researchers to propose that:
Studies include a statement on the constraints on generality (COG).
Assume that the relation between college entrance exam scores and first-year grade point average (GPA) is stronger than that between college entrance exam scores and second-year GPA. If two scatterplots were constructed to represent these data, how would they compare?
The cluster of points for college entrance exam scores and first-year GPA would more closely approximate a straight line
Mehl (2007) published in the journal science the results of an extensive study of 396 men and women, comparing the number of words uttered per day by each sex. Is the population likely to be normally distributed?
We do not know whether the population is normally distributed because we do not have information on the population
When a regression equation includes just one independent variable, the value of the standardized regression coefficient is:
the same as the Pearson correlation coefficient
Whenever a two-factor design 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
What does a two-way ANOVA offer beyond what two separate one-way ANOVAs can tell about the data?
A chance to see how the effect of one variable can depend on the levels of another variable.
What are two frequently used post-hoc tests?
Bonferroni and Tukey
What effect size is appropriate for a chi-square test?
Cramer's V
Although the hypothesis test can provide the probability that the levels of the independent variable lead to differences in the dependent variable, it is important to calculate effect size to:
Determine if the differences are large enough to matter
A consumer researcher examines the effectiveness of different body lotions by having 15 participants apply four different lotions to the same, unique body locations daily for two weeks. For example, lotion 1 is always applied to the right thigh, while lotion 2 is applied to the upper right arm. The participants were randomly selected at a drugstore in a busy area. What is the research hypothesis for this study?
Differences exist between the average effectiveness assessments of each lotion.
A traditional research paper has for major parts. This format is referred to as IMRAD. What does the D stand for?
Discussion
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where different participants are exposed to the different levels of the independent variable, the researcher would use a(n) _________ to analyze the data.
Independent-samples t test
A main effect for a two-way ANOVA is the:
Influence of one of the independent variables on the dependent variable.
Overall, children did not remember more words than adults on a memory test, F(1, 167) = 3.13, p > 0.05, and participants listening to music during the test did not remember more words than those not listening to music, F(1, 167) = 2.38, p > 0.05. However, listening to music significantly aided the children in remembering words, while it hindered the adults in remembering the words, F(1, 167) = 10.63, p < 0.05. Which effect(s) must be present in this study for these results to be valid?
Interaction of age and music
Dr. Holt is trying to determine which of her patients has the highest likelihood of developing depression. She calculates a linear regression equation using the scores on an anxiety measure, which are positively correlated with scores on a scale measuring depression. Dr. Holt converts patient D's anxiety score to a z score and predicts the z score for the depression scale to be -0.45. Is patient D's raw score for depression above or below the mean and why?
It is below the mean because the z score is negative
Which statistical analysis can handle multiple measures or repeated measures based on the same individual's?
One-way within groups ANOVA
Which symbol is NOT a type of sum of squares (ss) listed in a source table?
SSdegrees of freedom
It is helpful to represent the main effects and interactions of a factorial ANOVA graphically in a bar graph because when lines are drawn to connect the bars, they will be _______ if there is a main effect and _________ if there is an interaction.
Separate but parallel; intersecting
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where one level is represented by the sample and the other level is represented by a population for which the standard deviation is unknown, the researcher would use a(n) ____________ to analyze the data.
Single sample t test
When researchers use ANOVAs to report results of case studies that include only one participant, they typically violate the assumption of random selection. How does this action affect the conclusions of the study?
The external validity is low, and they cannot generalize their results beyond the sample
A developmental researcher found a significant result using a one-way ANOVA to compare the average language ability of four age groups (3 years old, 5 years old, 8 years old, and 11 years old). What specific conclusions can the researcher draw from this result?
The language abilities of the 3-, 5-, 8-, and 11-year-olds were not the same
A researcher is interested in the number of days spent unemployed and feelings of depression related to work. She recruits 82 unemployed professionals randomly from a list provided by her community unemployment office. She computes a correlation of -0.38. What decision would this researcher make for a two-tailed hypothesis test at a p level of 0.05?
The test statistic is significant, so she rejects the null hypothesis and concludes that the number of days spent unemployed is negatively correlated with feelings of depression.
The subjects sum of squares calculated in the one-way within-groups ANOVA assesses:
The variability due to participant differences
An independent variable that makes a separate and distinct contribution in the prediction of a dependent variable, as compared with another variable, is called:
an orthogonal variable
The standardized regression coefficient, which is equal to the Pearson correlation coefficient in a simple linear regression, is also called:
beta weight
For the three statistics, F, z, and t, divide ________ variability by ____________ variability to analyze the relation between variables.
between-groups; within-groups
Does attractiveness to people of different races or ethnic backgrounds depend on your own race or ethnicity? Mackenzie decides to collect data on this topic for a class project. She focuses on three different racial/ethnic groups for both the person and the subject of their attraction. What type of analysis could she use?
chi-square for independence
What is the best way to test whether males and females differ in their propensity to be either right-handed or left-handed?
chi-square for independence
Dr. Rapinoe is curious about whether the male and female soccer players at her university differ in their college majors. She collects data from members of both the men's and women's soccer teams and classifies their major into one of five categories: natural sciences, social sciences, formal sciences, applied sciences, and humanities. Which statistical test should Dr. Rapinoe use?
chi-square test for independence
The director of a preschool is interested in whether there is a tendency for fathers and mothers to be differentially involved in the care of their child, depending on the gender of that child. She collects data on which parent drops off a child and the gender of that child. Her preschool does not have that many children enrolled, so her data are limited. What statistical test could she use to analyze these data?
chi-square test for independence
A researcher wishes to investigate relations between depression and cerebral asymmetry. She collects EEG data from 50 subjects and classifies them as Right or Left-Frontal based on EEG asymmetry and using their HRSD scores classifies them as Depressed/non-depressed. What statistical test would be appropriate?
chi-square test of independence
A computer analysis that essentially calculates the average of every possible split-half correlation as a measure of reliability is known as:
coefficient alpha
When conducting a one-way within-groups ANOVA what is the formula for degrees of freedom error?
dferror = (dfbetween)(dfsubjects)
For a chi-square test of independence, we calculate the degrees of freedom using which formula?
dfx^2 = (krow-1)(kcolumn-1)
Outliers have little to no effect on the correlation coefficient
false
One of the primary limitations of nonparametric tests is that they:
have less statistical power than parametric tests
A researcher wishes to investigate relations between depression and cerebral asymmetry. She collects EEG data from 50 subjects and based on their HRSD scores classifies them as depressed/non depressed. What statistical test would be appropriate?
independent-samples t test
When conducting a Bonferroni test, we divide the overall p level by the:
number of comparisons
______________ is a branch of statistics focused on developing accurate and unbiased tests and measurements.
psychometrics
A consumer researcher examines the effectiveness of different body lotions by having 15 participants apply four different lotions to the same, unique body locations daily for two weeks. For example, lotion 1 is always applied to the right thigh, while lotion 2 is applied to the right upper arm. The participants were randomly selected at a drugstore in a busy area. Which assumption for the ANOVA is met?
random selection
You want to predict your score on the statistics final exam using your average quiz performance for the semester. Which statistical technique is best for this type of analysis?
simple linear regression
In the equation for a line in statistics, the _________ is the predicted amount of increase for Y when X is increased by 1, and the _________ is the predicted value for Y when X crosses the y-axis (X=0)
slope; intercept
The first step in calculating a correlation is to examine the data using a visual display.
true
A __________ is a hypothesis test that includes two nominal independent variables and an interval dependent variable, and a _____________ is a statistical analysis used with one interval dependent variable and at least two nominal independent variables.
two-way ANOVA; factorial ANOVA
Psychometrics is the branch of statistics:
used in the development of tests and measurements
What are three circumstances in which we commonly use a nonparametric test?
when the dependent variable is nominal, either the independent variable or dependent variable is ordinal and when the sample size is small and an underlying population distribution is suspected to be skewed
The multiple-group equivalent of a paired-samples t test is the:
One-way within-groups ANOVA
Strength of Correlation
- a correlation is stronger if it is farther (in either direction) from zero - stronger r, closer individual data points group around the line - Think of r as amount of "cluster" or "hug" around best fitting line through the data
Which value represents the strongest relation between two variables?
-0.44
A consumer researcher examines the effectiveness of different body lotions by having 15 participants apply four different lotions to the same, unique body locations daily for two weeks. For example, lotion 1 is always applied to the right thigh, while lotion 2 is applied to the right upper arm. How many post hoc tests will be needed to determine where significant differences occurred?
6
Body mass index can be predicted based on the amount of calories consumed by an individual due to the positive correlation between the two variables. When looking at the line of best fit for the linear regression, the data points are clustered close together. Predicted shyness based on the number of friendships a person has is also correlated, but the data points are more scattered around the line of best fit, showing a general negative correlation. Which has the higher predictive power, and why?
Calories consumed and body mass index, becuase the variance is lower
A researcher wishes to investigate relations between depression and cerebral asymmetry. She collects EEG data from 50 subjects and assesses their level of depression on the Hamilton Rating Scale for Depression (HRSD). What statistical test would be appropriate?
Correlation
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where different participants are exposed to the different levels of the independent variable, the researcher would use a(n) ____________ to analyze the data.
Independent-samples t test
There is an extremely high negative correlation between altitude and the percentage of oxygen in the air. Is it correct to say that high altitudes cause low amounts of oxygen in the air based on a linear regression equation and the Pearson correlation coefficient?
No, because regression analysis does not imply causation
When a psychological researcher conducts a within-groups ANOVA, she fails to find a significant F statistic for the independent variable and finds an R2 value of 0.02. What does the effect-size tell the researcher about the research?
The conventions for R2 indicate that this is a small effect, which would help to explain the nonsignificant F statistic.
Which of these is NOT an assumption of a two-way between-groups ANOVA?
The participants are matched on important characteristics.
Assume a positive correlation is found between the number of hours students spend studying for an exam and their grade on the exam. If the regression equation for these data is calculated and the y intercept is 64, what conclusion can be drawn?
When students do not study at all, we would predict a score of 64 on the exam.
A correlation coefficient is a statistic that:
quantifies the relation between two variables
Each time Roberta takes a certain IQ test, she scores 100. It can be concluded that the IQ test is:
reliable
Multiple regression differs from simple linear regression in that it:
uses more than one independent variable to make predictions
As the number of t tests increases, the risk of a Type 1 error decreases.
False
A psychopathology researcher compares depression levels of individuals residing in five different climate regions. She collects data from 15 randomly selected people in each region. If she compares her groups using a between-groups, one-way ANOVA at a p level of 0.05, the critical value for her F statistic would be:
2.50
A cognitive researcher compares mental functioning in retired professional athletes across three different sports. He computes a series of three t tests to examine all between-group differences, running each test with a p level of 0.01. What is the probability of a Type I error when making these comparisons?
0.03 or a 3% chance
Susan is figuring the regression line for some data but needs help in first figuring the predicted value of Y. She knows that the slope is 2 and the intercept is 7. What is the predicted Y value for an X score of 7?
21
The range of the correlation coefficient is always:
-1.0 to 1.0
A multiple regression analysis revealed the following equation relating the time (in hours) it takes to complete a puzzle based on the number and size of pieces: Y = 1.6 + 0.02 (Xnumberofpieces) - 1.25 (Ysizeofpieces). If a puzzle has 1000 pieces, with a size value of 0.4 inch, how long will it take to complete?
21.1 hours
When we conduct a one-way repeated measures ANOVA, we calculate _________ F statistics and we are actually interested in __________ F statistics.
2;1
A researcher interested in the effects of "casual Fridays" on employee productivity decides to study the impact of attire at work. She randomly selects 36 people at a large company to participate. Across the course of three weeks, she has all 36 participants experience working under three different levels of work attire: casual, dress-casual, and formal attire. How many post hoc tests will be needed to determine where significant differences occured?
3
If between groups variance is 8 and within-groups variance is 2, what would F be?
4 (8/2)
A researcher sets up a study to examine how lecture comprehension of college students is affected by lecture type (economics, psychology, statistics, or chemistry), classroom size (large or small), presentation method (blackboard, overhead projector, or computer), and instructor (graduate student, assistant professor, full professor). How is the design described?
4 x 2 x 3 x 3 between-groups ANOVA
Dr. Frost conducts a study investigating the number of externalizing behaviors amongst men and women with one of four different psychological disorders: depression, GAD, schizophrenia, and social phobia, and recruits 8 participants in each condition. What is the dfwithin for this factorial design?
56
A consumer researcher examines the effectiveness of different body lotions by having 15 participants apply four different lotions to the same, unique body locations daily for two weeks. For example, lotion 1 is always applied to the right thigh, while lotion 2 is applied to the upper right arm. How many post hoc tests will be needed to determine where significant differences occurred?
6
A 3 by 4 factorial between-groups design has 6 subjects in each cell. What is the dfwithin?
60
A researcher sets up a study to examine how lecture comprehension of college students is affected by lecture type (economics, psychology, statistics, or chemistry), classroom size (large or small), presentation method (blackboard, overhead projector, or computer), and instructor (graduate student, assistant professor, full professor). How many cells are in this design?
72
The mean square within-groups, sometimes referred to as mean square error, in a between-groups ANOVA is
All of the above: the average of the individual sample variances provided that there are equal N's, the weighted average of all the sample variances, an estimate of the variance of each of the populations involved.
Which of these is a reason why a cause-effect relationship is NOT assumed in correlational studies?
Another variable could be causing the effects in both variables of interest
The correlation coefficient between two variables, height and IQ score, is zero. What does this statement mean?
As the value of one variable changes, the other is not necessarily affected.
It has been suggested that the rate of forgetting (normal versus fast) for the word lists often used in psychological experiments may depend on the type of memory test employed, either free-recall or recognition. What is the best way to test this hypothesis?
Chi-square test
When a magazine surveyed 250 men and 3000 women, 52% of the male participants said that football was their favorite sport, and 30% of the female participants also reported football as their favorite. All participants were asked to select from four sports. How could this be tested if this difference is significant, given that the samples were uneven?
Chi-square test for independence, converting the data into frequencies for a contingency table
Which of these is a potential problem with attempts at replicating previously published research?
Earlier research may have been conducted with WEIRD samples.
Which of the following is considered one of the "new statistics" that APA now requires of researchers submitting paper for publication?
Effect size
When using a chi-square test for independence, you compute the ____________ frequencies which are frequencies you would observe if the variables are independent of each other.
Expected
A cognitive psychologist is interested in whether there are gender differences in verbal and spatial abilities. The psychologist recruits 48 men and women and has them complete tests of verbal and spatial ability based on the Weschler intelligence test. The psychologist should use a ________ to analyze these data.
Factorial ANOVA
A p-value is the probability that the null hypothesis is true.
False
As the correlation between two variables increases, the proportionate reduction in error decreases.
False
Below is the F statistic which indicates the ratio of two measures of variability. If the within-groups variance is much larger than the between-groups variance, we can infer that there is a significant difference between means. F = between-groups variance/within-groups variance
False
Carli visually inspects her data before analyzing it, only to find that the populations that she sampled appear to have very different variances although her sample sizes are equal. Which assumption of ANOVA has she violated, and what should she do?
Homoscedasticity; she should proceed as long as the largest variance is not greater than two times the smallest variance and report it with her statistics
If a person's score on a(n) _____________ variable is known, the person's score on the ___________ variable can be predicted using simple linear regression.
Independent; dependent
Dr. Holt is trying to determine which of her patients has the highest likelihood of developing depression. She calculates a linear regression equation using the scores on an anxiety measure, which are positively correlated with scores on a scale measuring depression. Dr. Holt converts patient D's anxiety score to a z score and predicts the z score for the depression scale to be 0.62. Is patient D's raw score for depression above or below the mean and why?
It is above the mean because the z score is positive
A cell depicts one unique combination of _______ of the independent variable in a two-way ANOVA
Levels
Jillian wants to test how different levels of verbal ability and math ability influence a measure of reading comprehension and a measure of graph interpretation. She is concerned that IQ may confound the results because it is likely to have an effect, too. What test should she use to account for this third variable?
MANCOVA
A research study with a factorial design is set up where there are two independent variables (gender of participant and age of participant) and the dependent variable is memory performance. After the data from the experiment is analyzed, it is found that females remembered more than males. We can say that there is a(n) ______________ of gender of participant.
Main effect
A study found that rats that received a drug took longer to find their way out of a maze than rats that received a placebo, F(1,57) = 6.23, p < .05. The drug had a large effect on albino rats and virtually no effect on wild-bred rats, F(1,57) = 10.61, p < .05. However, there was no overall difference in the time of albino rats compared to that of wild-bred rats, F(1,57) = 1.29, p > .10. Which effect(s) must be present for these results to be true?
Main effect of drug and an interaction of drug and rat species
In determining main effects and interactions in a factorial ANOVA, it is helpful to use the ______ in a table of means.
Marginal means
__________ refers to the means of the rows and the means of the columns in a table that shows the cells of a study with a two-way ANOVA design.
Marginal means
All of the following statements are true of matched group designs EXCEPT:
Matched group designs typically involve testing fewer participants than within-groups designs
In which section of a research report does the researcher provide information about whether the study was preregistered?
Methods
For an F distribution with 3 degrees of freedom between and 32 degrees of freedom within, how many groups are being compared and how many participants per group?
NOT 3 groups, 32 participants OR 4 groups, 8 participants
A social scientist interested in the effects of "casual Fridays" on work performance decides to study the impact of attire at work. She randomly selects 35 people at a large company to participate. Over the course of three weeks, she has all 35 participants experience working under three different levels of work attire: casual, dress-casual, and formal attire. What statistical analysis would be appropriate for her design?
One-way within-groups ANOVA
The National Collegiate Athletic Association (NCAA) cares about success for athletes both in their sports and in their education. A researcher hired by the NCAA wants to know how athletes' academic performance is affected by the stage of their competitive season. She examines performance in the preseason throughout the active competitive season, and in the postseason, 150 athletes, from across several different sports, are assessed during each period. What statistical analysis would be appropriate for this research?
One-way within-groups ANOVA
The Open Science Framework has developed different badges to recognize ethical and transparent practices. Which badge indicates that the researchers have made their raw data available to anyone wishing to conduct their own analyses?
Open Data
What statistical test should a researcher use when examining the relation between two scale variables?
Pearson correlation
A researcher is examining the relation between patrol location (more affluent versus less affluent neighborhoods) and amount of training (5 weeks, 10 weeks, or 15 weeks) to police job performance in a small town. The researcher finds a significant interaction in that the strength of the direction of the effect does not change. This type of effect is a:
Quantitative interaction
When performing a two-way between-groups ANOVA, effect size is measured using _______, and it is calculated for _________ effects.
R2: three
To find the effect size for ANOVA we calculate
R^2
A psychology advisor wishes to see if students' grade point averages are predictive of their GRE scores when they apply to graduate school. To investigate this question, the advisor should us a:
Regression
____________ is a useful statistical analysis for predicting behavior, and ______________ is a useful technique for finding the direction and strength of a relation between two variables.
Regression; correlation
In a within-subjects ANOVA, Nolan & Heinzen use the label SSwithin to correspond to what term that we use in our source table?
SSerror
When calculating R2 (effect size) for the one-way within-groups ANOVA we do not have to be concerned with the calculation for
SSerror
Otis thinks some college students spend more money during the semester than others and that this difference is related to the students' majors. He wants to compare the total amount of money spent at the end of one semester by 48 American college students who major in psychology to that spent by chemistry or English majors. What is the second step Otis should follow for testing his hypothesis?
State the null hypothesis as "college students majoring in psychology, chemistry, or English spend about the same amount of money during one semester, on average". State the research hypothesis as "college students majoring in psychology, chemistry, or English do not spend the same amount of money during one semester, on average"
A student researcher conducts a study that is analyzed using a two-way between-groups ANOVA. Unfortunately, none of the three F statistics was statistically significant. The student is confident that her research question is an important one, and she wonders if she simply didn't collect enough data to detect anything. She computes effect size measures and gets the following values: 0.013 for the first main effect, 0.082 for the second main effect, and 0.0027 for the interaction. If she were to conduct additional research, what would you recommend she pursue?
The second main effect because it has a medium effect size.
A bar graph displays the mean scores on a test of mental rotation for students majoring in psychology or engineering who have either high or low spatial abilities. Psychology and engineering students with low spatial skills scored about 32% correct on the mental rotation test, while psychology and engineering students with high spatial skills scored about 68% correct. What can be inferred from these data?
There appears to be a main effect of spatial ability only.
An experimenter rejects the null hypothesis after using an F table to determine the significance value. What can be concluded?
There is a difference between means that is larger than we would predict by chance
One limitation of nonparametric tests is that confidence interval and effect size measures are typically not available. Which statement is true of chi-square tests?
There is a measure of effect size, Cramer's V
An experimenter fails to reject the null hypothesis after using an F table to determine the significance value. What can be concluded?
There is no difference between means
All other things being equal, a correlation of r = .60 will result in more accurate prediction than a correlation of r = .50.
True
The testing service on your campus is conducting a study to determine how method of presentation (standard lecture versus computer presentation) and type of lecture (psychology, economics, statistics) relate to lecture comprehension. What kind of ANOVA should testing services use and what are the factors and/or levels?
Two-way ANOVA: factor 1 is presentation, with two levels (standard versus computer), and factor 2 is lecture type, with three levels (psychology, economics, and statistics).
When comparing three or more groups we use ANOVA. It would be incorrect to instead conduct multiple t tests. Doing so would increase the chances of making a:
Type I error
For a chi-square test for goodness of fit, what must be true to receive empirical support for the research hypothesis?
We are actually hoping for a bad fit between the observed data and what we expect according to the null hypothesis
When determining the critical value or cutoff for the three effects tested in a two-way between-groups ANOVA, what value is always the same for each effect?
Within-groups degrees of freedom
Does the F distribution take into account individual differences when comparing sample means?
Yes; as the variability within the individual samples decreases, the F statistic becomes larger since the distributions are not overlapping very much.
One difference between the one-way between-groups ANOVA and the one-way within-groups ANOVA is that only with the one-way within groups ANOVA
You must be concerned about order effects
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where on level is represented by the sample and the other level is represented by a population that has a known mean and a standard deviation, the researcher would use a(n) ___________ to analyze the data.
Z test
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where one level is represented by the sample and the other level is represented by a population that has a known mean and standard deviation, the researcher would use a(n) _____________ to analyze the data.
Z test
How is a correlation different from a regression analysis?
a regression enables us to make predictions, while a correlation describes relationships
Standardized regression coefficient
a standard version of the slope in a regression equation, is the predicted charge in the outcome variable in terms of standard deviations for an increase of 1 standard deviation in the predictor variable; symbolized by b and often called beta weight
There is a correlation between eating dinner together as a family and a decreased risk of drug addiction in teenagers. The most likely explanation is that:
a third variable causes both effects
The chi-square test for _________ is appropriate when there is one nominal variable, whereas the chi-square for __________ is appropriate when there are two nominal variables
goodness of fit; independence
If variances between groups are equal, we refer to this as:
homoscedasticity
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where different participants are exposed to the different levels of the independent variable, the researcher would use a(n) ___________ to analyze the data.
independent-samples t test
Although nonparametric tests such as chi-square can be used with populations that are not normally distributed, there is still an important assumption that the data are ________.
independently sampled from the population
In the simple linear regression formula, _____________ is the predicted value for Y when X is equal to 0.
intercept
Predicting an individual's grade on a final exam from two variables - for example, midterm test grade and percentage of classes attended - would involve the use of:
multiple regression
_______________ tests are useful for comparisons of data where the dependent variable is _________
nonparametric; nominal
A researcher wishes to investigate relations between depression and cerebral asymmetry. She collects EEG data from 50 subjects and based on their HRSD scores classifies them as severley depressed/moderately depressed/non-depressed. What statistical test would be appropriate?
one-way between-groups ANOVA
Margot works for an advertising firm and needs to understand how an individual's levels of experience with cooking (novice, intermediate, or expert) affect how he or she will rate a new group of cookware advertisements. What type of design would be best for Margot to use?
one-way between-groups ANOVA
The National Collegiate Athletic Association (NCAA) cares about success for athletes both in their sports and in their education. A researcher hired by the NCAA wants to know how athletes' academic performance is affected by the stage of their competitive season. She examines performance in the preseason, throughout the active competitive season, and in the postseason; 150 athletes from across several different sports, are assessed during each period. What statistical analysis would be appropriate for this research?
one-way within-groups ANOVA
When a researcher investigates a question involving a scale dependent variable and a single nominal independent variable (IV) with three or more levels in which participants receive all levels of the IV, which statistical test should the researcher employ?
one-way within-groups ANOVA
Which statistical analysis can handle multiple measures or repeated measures based on the same individuals?
one-way within-groups ANOVA
A simple regression allows us to use _________ independent variable(s) while a multiple regression analysis allows us to use ____________ independent variable(s).
one; two or more
When a researcher is investigating a question involving a scale dependent variable and a nominal independent variable with two levels where participants are exposed to both levels of the independent variable, the researcher would use a(n) __________ to analyze the data.
paired-samples t test
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 called a:
partial correlation
As the age of a male professor increases, his income increases. This is an example of what type of correlation?
positive
Every week this past summer, Jason has recorded the number of times it has rained and the height of all of this tomato plants. He wants to see if the two are correlated, so he creates a scatterplot of the data. He sees a pattern that he could probably draw a line through (from the bottom left going up to the top right), as rainy days and plant height both increase. What type of correlation is this?
positive
Regression is a type of statistical analysis that is most used for:
predicting behavior
When using a one-way within-groups ANOVA, the variability due to individual differences is _________, resulting in a _________ F statistic.
reduced; larger
The formula for correlation is similar to the formula for z score in that both:
take into account sample size and variability
When a research design involves on nominal variable, what nonparametric hypothesis test is used?
the chi-square test for goodness of fit
The one-way within-groups ANOVA has a new source of variability known as the subjects sum of squares. To calculate this sum of squares, the researcher subtracts:
the grand mean from each participant's mean for all of his or her scores
When conducting hypothesis testing for the Pearson correlation coefficient, r, we calculate degrees of freedom by subtracting 2 from the sample size. In Pearson correlation, the sample size is:
the number of participants
The term coefficient of determination is also known as:
the proportionate reduction in error
When conducting a one-way between-groups ANOVA how many sums of squares are calculated?
three
If a researcher expects that a new teaching technique will be more effective for high school students than for younger middle school students, then the researcher is predicting an interaction between teaching style and grade school.
true
When performing a hypothesis test for correlation, we test against the null hypothesis the p = 0.0
true