PY 355 Exam 4 reading quiz

Which of the following correlation coefficients reflects the strongest relationship between two variables?

-.60

The central threat to the internal validity of a simple interrupted time series design is -maturation -contemporary history -regression to the mean -pretest sensitization -selection bias

-contemporary history

Longitudinal designs are superior to cross-sectional designs for studying age-related changes in behavior because they -use random assignment -control for generational effects -use control groups -eliminate confounding -have greater external validity

-control for generational effects

The primary difference between quasi-experiments and true experiments is that quasi-experiments -require fewer participants -do not involve random assignment -have no dependent variable -involve a single participant -are conducted outside of a laboratory

-do not involve random assignment

Compared to true experiments, quasi-experiments tend to -have lower internal validity -involve more participants -use simpler designs -be used more for research on animals -have lower external validity

-have lower internal validity

The biggest threat to internal validity in a nonequivalent control group pretest-posttest design is -maturation -local history -external invalidity -experimenter expectancy -posttest reactivity

-local history

Which of the following confounds is most likely in research that studies children over time? -regression to the mean -selection bias -history -pretest sensitization -maturation

-maturation

Which of the following is not a criterion for inferring causality? -the cause and the effect covary -alternative explanations of the results are eliminated -the causal variable precedes the hypothesized effect -participants must be randomly assigned to conditions -a systematic relationship is observed between the cause and effect

-participants must be randomly assigned to conditions

A researcher is hired to document the effects of a management seminar on managers' effectiveness. This kind of research is -critical multiplism -program evaluation -quasi-experimentation -outcome analysis -decision research

-program evaluation

Longitudinal designs most closely resemble -time series designs -one-group pretest-posttest designs -factorial experiments -demographic studies -correlational research

-time series designs

Contemporary history is a problem -in all experimental and quasi-experimental designs -when one group experiences an event that another group does not experience -in research that deals with current events -when another event occurs at the same time as the quasi-independent variable -in program evaluation research

-when another event occurs at the same time as the quasi-independent variable

A local history effect occurs -because participants were not randomly assigned to groups -when external validity is low -as a result of regression to the mean -all of the participants are from the same locality -when groups experience different events other than the quasi-independent variable

-when groups experience different events other than the quasi-independent variable

What is the mean of these data: 2, 4, 5, 4, 4, 1, 1?

3

In a normal distribution, approximately what percentage of scores falls between the mean and one standard deviation above the mean?

34%

"What is the median of these data: 2, 2, 5, 4, 6, 6, 1?"

4

effect size

Index of the strength of the relationship between the independent variable and dependent variable that is independent of sample size.

"John has a z-score of -2.8, whereas Mary has a z-score of + 1.9. Whose score is more extreme?"

John's

Type 1 error

Rejecting null hypothesis when it is true

t (obtained)

The test statistic computed in step 4 of the five-step model. The sample outcome expressed as a t score

t-test

a statistical test used to evaluate the size and significance of the difference between two means

most experiments in psychology use a. convenience samples b. simple random samples c. stratified random samples d. purposive samples e. none of the above

a. convenience samples

"the goal of most psychology research is to test hypotheses regarding how certain psychological variables relate to one another, not to describe how a population behaves. Therefore," a. probability samples are rare in psychology b. cluster samples provide the most accurate estimations in psychology c. convenience samples should be avoided in psychological research d. nonresponse is not a problem in psychology e. simple random samples are required in psychological research

a. probability samples are rare in psychology

researchers want to test the number of people who prefer Coke over Pepsi and so ask every third pedestrian on a busy sidewalk which they prefer. This is an example of a. systematic shaping b. purposive sampling c. cluster sampling d. quota sampling

a. systematic sampling

the probability that a researcher is willing to make a Type I error is a. the alpha-level b. the calculated value of t c. beta d. the null hypothesis e. error variance

a. the alpha-level

a power analysis is often used to determine a. the number of participants needed for a study b. the likelihood of making a Type I error c. the strength of the independent variable d. wether to reject the null hypothesis e. the alpha-level

a. the number of participants needed for a study

In factor analysis, a one-factor solution will be obtained when...

all variables are highly correlated

A researcher obtained a correlation of +.45 between Variable A and Variable B. What is the best interpretation of this correlation?

as scores of A increase, scores of B increase

"when a probability sample is used, the researcher is able to specify the probability that" a. the obtained results are accurate b. any individual in the population will be in the sample c. the sampling error is zero d. the sample is random e. the sample is properly stratified

b. any individual in the population will be in the sample

one-tailed is to two-tailed as a. alpha is to beta b. directional is to nondirectional c. randomized is to matched d. posttest only is to pretest-posttest e. type II is to type I

b. directional is to nondirectional

if a significant main effect involves an independent variable with two conditions, the main effect is interpreted by a. testing the simple main effects b. inspecting the means c. conducting an ANOVA d. doing follow-up or post hoc tests e. testing the interaction

b. inspecting the means

if statistical analyses show that the difference between condition means is larger than would be expected on the basis of error variance alone, a researcher will a. accept the null hypothesis b. reject the null hypothesis c. fail to reject the null hypothesis d. reject the experimental hypothesis e. both a and d

b. reject the null hypothesis

if the calculated value of F is 6.56 and the critical value of F is 4.36, the researcher will a. make a Type I error b. reject the null hypothesis c. conclude that the group means do not differ d. perform a t-test e. conclude that confounding has occured

b. reject the null hypothesis

"when determining the size of a sample, researchers typically" a. choose 3% of the population for the sample b. select an economic sample c. select as large a sample as possible d. use samples of approximately 300 individuals e. rely on a quota system

b. select an economic sample

the calculated value of t is the ratio of a. the error variance to sample size b. the difference between means to error variance c. population variance to sample variance d. degrees of freedom to variance e. alpha to beta

b. the difference between means to error variance

which of the following is an advantage of cluster sampling over simple random sampling in many cases? a. the error of estimation is lower b. the respondents may be close together geographically c. it is more representative of the population d. it is a non probability sampling procedure e. the required sample size is smaller

b. the respondents may be close together geographically

the literary digest election survey of 1936 led to an incorrect prediction because a. the sample size was too small b. the sample was not representative of US voters c. the error of estimation was too high d. a stratified random sample was used e. the survey questionnaire was not valid

b. the sample was not representative of the US voters

if the independent variable has absolutely no effect on participants' responses, all of the variance int he data is ___ variance a. reliable b. between-groups c. error d. dependent e. mean square

c. error

if statistical analysis show that the difference between condition means is no larger than would be expected on the basis of error variance alone, a researcher will a. accept the null hypothesis b. reject the null hypothesis c. fail to reject the null hypothesis d. reject the experimental hypothesis e. both a and d

c. fail to reject the null hypothesis

to identify which means differ following a significant F-est, researchers use a. sum of squares b. t-tests c. follow-up tests d. ANOVA e. interaction tests

c. follow-up tests

a simple main effect is a. a main effect that is statistically significant b. an interaction c. the effect of an independent variable at a particular level of another independent variable d. a post hoc test e. the difference between two significant main effects

c. the effect of an independent variable at a particular level of another independent variable

why do researchers not conduct several t-tests to analyze experiment that have more than two conditions? a. the means will be invalid b. the sample size is too small c. type I error is inflated d. the power of the analysis is low e. all of the above

c. type I error is inflated

On a histogram, the x-axis presents the

class intervals

Most correlational research satisfies which of the following criteria for determining causality?

covariation

if we divide the total sum of squares by (n-1), we get a. SSwg b. MSbg c. SStotal d. MStotal e. MSwg

d. MStotal

multivariate analysis of variance is used to a. analyze data from designs with several independent variables b. uncover factor structure c. protect against Type II error d. analyze a set of dependent variables e. conduct a within-subject analysis

d. analyze a set of dependent variables

MANOVA analyzes a composite variable that is the sum of the weighted dependent variables. This composite variable is the a. discriminant function b. canonical correlation c. factor loading d. canonical variable e. multivariate test

d. canonical variable

if a significant main effect involves an independent variable that has more than two conditions, the main effect is interpreted by a. testing the simple main effects b. visually inspecting the means c. conducting an ANOVA d. doing post hoc tests e. testing the interaction

d. doing post hoc tests

the proportion of the variability in a dependent variable that is due to the independent variable is a. power b. statistical significance c. beta d. effect size e. the critical value

d. effect size

"when a researcher generalizes results to a population that differs from eh one from which the sample was drawn, this is called" a. nonresponse b. non probability sampling c. representative sampling d. misgeneralization e. stratification

d. misgeneralization

a directional hypothesis a. requires a paired t-test b. stipulates whether alpha or beta is most important c. requires more participants than a nondirectional hypothesis d. predicts which of two means will be larger e. tests whether error variance is smaller or larger than systematic variance

d. predicts which of two means will be larger

"when researchers use past research to findings or their judgment to decide which participants to include in the sample, they are using " a. quota sampling b. representative sampling c. probability sampling d. purposive sampling e. economic sampling

d. purposive sampling

"when researchers want to ensure that a certain kinds of participants in a convenience sample are obtained in particular proportions, they use" a. representative sampling b. probability sampling c. purposive sampling d. quota sampling e. economic sampling

d. quota sampling

sampling error a. reflects researchers mistakes in collecting data b. is greater with large than small samples c. should be as large as possible d. reflects differences between the sample and population e. is eliminated by using probability samples

d. reflect differences between the sample and the population

if the calculated value of t exceeds the cortical value of t, the researcher a. fails to reject the null hypothesis b. commits a Type I error c. has made a calculation error d. rejects the null hypothesis e. conducts an F-test

d. rejects the null hypothesis

a sample from which a researcher can draw accurate inferences about the population is a a. systematic sample b. sampling frame c. quota sample d. representative sample e. stratum

d. representative sample

sample is to population as is to a. variance; standar deviation b. whole; part c. probability; non probability d. some;all e. systematic; unsystematic

d. some;all

a subset of a population that shares a particular characteristic is called a a. representative group b. sample frame c. quota d. stratum e. stereotype

d. stratum

if we calculate the sum of squares separately for each experimental condition, the sum then, we get a. the total sum of squares b. mean square within-groups c. means square between-groups d. sum of squares within-groups e. sum of squares between-groups

d. sum of squares within-groups

A researcher is studying patterns of marriage and divorce among people who live below the poverty line in 10 major cities. This is an example of _________ research.

demographic

Research that describes the characteristics or behaviors of a given population in a systematic and accurate fashion is called __________ research.

descriptive

error variance

deviation of the individual scores in each group from their respective group means

A researcher predicts that variable X has a positive relationship with variable Y. This is a...

directional hypothesis

How would you convert a grouped frequency distribution to a relative frequency distribution?

divide the frequency of each class interval by the total number of scores

increasing the sample size results in: a. increased power b. smaller error of estimation c. increased representativeness of the sample d. a, b, and c are correct e. a and b are correct

e. a and b are correct

"if a survey researcher reports that her results are accurate within four percentage points, four percent is the" a. sampling frame b. stratum c. quota d. error of estimation e. probability

e. error of estimation

the ability of a research design to detect any effects that exist in the data is called a. stratum b. economic sampling c. generalization d. estimation e. power

e. power

a difference between means that is statistically significant is a. due to error variance b. not likely to be a type II error c. a null finding d. greater than the calculated value of t e. unlikely to be due to error variance

e. unlikely to be due to error variance

Type 2 error

failing to reject a false null hypothesis

A correlation of +.60 is _________ as strong as a correlation of +.30.

four times

Which of the following is a graphical method of describing numerical data?

frequency histogram and frequency polygon (both b and c are correct)

On a histogram, the y-axis presents the

frequency of each score

On a scatterplot, a correlation coefficient of .00 appears as a...

horizontal line

correct decision

if the Null hypothesis is false than you should reject the null hypothesis and if you don't then it's a type 2 error, but if the Null hypothesis is true then you should fail to reject the null and if you don't then it is a type 1 error.

A correlation coefficient of a given magnitude is more likely to be statistically significant when...

it is based on a large rather than a small number of scores

A frequency polygon is a

line graph

On a scatterplot, a correlation coefficient of +1.00 appears as a...

line that slopes upward to the right

Which measure of central tendency is used most often?

mean

What are the measures of central tendency?

mode, median, and mean

The standard deviation is

none of the above (the square of the variance, more difficult to interpret than the variance, the inverse of the range, the difference between the largest and smallest score)

Extreme scores in a sample are called

outliers

In a (an) __________ survey design, a single group of participants is questioned more than once

panel

A distribution in which there are more low scores than high scores is

positively skewed

Alpha

probability of making a Type I error; and erroneously believing that an effect was obtained when it was actually due to error variance

Beta

probability of making a type II error; and erroneously failing to find an effect was obtained when it was actually due to error variance

A z-score

reflects how far a participant's score falls from the mean

failing to reject the null hypothesis

researcher concludes that the null hypothesis is correct and that the independent variable did not have an effect

reject the null hypothesis

researcher concludes that the null hypothesis is wrong and that the independent variable had an effect on the dependent variable

Mean difference effect size (d)

size of the difference between two means relative to the standard deviation of the data; typically ranges from -3.0 to +3.0 (although can be larger)

directional hypothesis

states which of the two condition means is expected to be larger (use one-tailed test)

On a scatterplot, a correlation of -1.00 appears as a...

straight line that slopes down and to the right

A partial correlation is...

the correlation between two variables with the influence of other variables removed

If the variability in a set of data is small

the mean is representative of the scores

systematic variance

the portion of the total variance in a set of scores that is related in an orderly, predictable fashion to the variables the researcher is investigating

In the regression equation, y = 5.18 - 1.30x, x is...

the predictor variable

proportion of variance effect size

the proportion of variability in the dependent variable that is due to the independent variable; ranges from .00 to 1.00

The coefficient of determination is...

the proportion of variance in one variable that is accounted for by another

In the regression equation, y = .78 + .67x, .67 is...

the regression coefficient

Regression analysis is often used...

to predict scores

degrees of freedom

total number of participants minus the number of conditions

null hypothesis

when the independent variable did not an effect on the dependent variable