Research Methods and Test construction

Question 1

In the context of psychological assessment, the terms “floor” and “ceiling” refer to:

A. the lowest and highest true scores an examinee is likely to have, given his or her obtained predictor score.

B. the lowest and highest scores an examinee is likely to obtain on a criterion, given his or her predictor score.

C. the degree to which a test can discriminate among examinees who have very low levels or very high levels of the characteristic measured by the test.

D. the degree to which a test accurately predicts the criterion scores of examinees who obtain very low scores or very high scores on the test.

Answer 1

A test has limited floor when it cannot discriminate well among examinees who have a low level of the characteristic measured by the test because the test does not include a sufficient number of easy items. In contrast, a test has limited ceiling when it cannot discriminate well among examinees who have a high level of the characteristic measured by the test because it does not include a sufficient number of difficult items.

Question 2

A psychologist is planning a research study to evaluate the effects of a two-hour online lecture on statistics for improving the statistics knowledge of 35 psychologists who have just started studying for the EPPP. All participants will (1) take a pre-test consisting of 50 multiple-choice statistics questions on Monday, (2) attend the online lecture on Wednesday evening, and (3) take a post-test consisting of 50 multiple-choice statistics questions that are equivalent to the pre-test questions on Friday. To analyze the data she obtains in her study, the researcher will use which of the following?

A. t-test for a single sample

B. t-test for correlated samples

C. two-way ANOVA

D. single-sample chi-square test

Answer 2

The first steps in identifying the appropriate statistical test are to identify the independent and dependent variables and the scale of measurement of the dependent variable. This study’s independent variable is the lecture on statistics and the dependent variable is statistics test score. The dependent variable is measured on a ratio scale, which means that the statistical test will be used to compare the mean scores obtained by the psychologists on the pre- and post-tests. The t-test and ANOVA are both used to compare mean scores, but because there are only two means, the t-test is the appropriate test. To determine which t-test to use, you determine how the means will be obtained: In this study they will be obtained from a single group of subjects, and the t-test for correlated samples is used when two means are obtained from the same group or from two groups that are related in some way.

Question 3

Which of the following is a culture-reduced measure of fluid intelligence?

A. Kuhlmann-Anderson

B. Raven’s Progressive Matrices

C. Woodcock-Johnson

D. Slosson Intelligence Test

Answer 3

The Raven’s Progressive Matrices (RPM) tests are measures of fluid intelligence and are considered to be culture-reduced because they do not use language and performance does not depend on specific cultural or academic learning. There are three RPM tests: Standard Progressive Matrices, Colored Progressive Matrices, and Advanced Progressive Matrices.

Question 8

Which of the following is a type of counterbalanced design?

A. Solomon four-group

B. Latin square

C. factorial

D. multiple-baseline

Answer 8

Counterbalancing is used to control order effects that may occur when a within-subjects design is used – i.e., when subjects in each group will receive or participate in all levels of the independent variable. The Latin square is a type of counterbalanced design that ensures that the different levels of the independent variable are assigned to the groups of subjects so that each level appears an equal number of times in each ordinal position.

Question 9

Which of the following best describes ethical requirements regarding sexual relationships with students?

A. Psychologists are prohibited from becoming sexually involved with current and former students in their department.

B. Psychologists are prohibited from becoming sexually involved with students who are “vulnerable to undue influence.”

C. Psychologists are prohibited from becoming sexually involved with students when doing so creates an unacceptable multiple relationship.

D. Psychologists are prohibited from becoming sexually involved with students over whom they have or are likely to have evaluative authority.

Answer 9

Correct answer

D. Psychologists are prohibited from becoming sexually involved with students over whom they have or are likely to have evaluative authority.

This is the best answer because it’s closest to the language of Standard 7.07 of the APA Ethics Code and Standard II.29 of the Canadian Code of Ethics, which prohibit psychologists from becoming sexually involved with students who are in their departments or over whom they have evaluative authority.

Question 10

The Generations Study (Bishop et al., 2020) compared the timing and pacing of sexual identity development for lesbian, gay, and bisexual individuals ages 18 to 26, 32 to 43, and 50 to 60. The results of the study found that:

A. members of the three age cohorts reported similar ages of onset for all milestones and similar lengths of time between milestones.

B. members of the youngest age cohort reported the earliest ages of onset for all milestones, but members of all three age cohorts reported similar lengths of time between milestones.

C. members of the youngest age cohort reported the earliest ages of onset for all milestones, but members of the oldest age cohort reported the shortest lengths of time between milestones.

D. members of the youngest age cohort reported the earliest ages of onset for all milestones and the shortest lengths of time between milestones.

Answer 10

Correct answer
D. members of the youngest age cohort reported the earliest ages of onset for all milestones and the shortest lengths of time between milestones.
Participants in the Generations Study were asked about the ages when they first experienced five sexual identity milestones:
1. awareness of same-sex attraction;
2. self-identification as lesbian, gay, or bisexual;
3. same-sex sexual behavior;
4. disclosure as a sexual minority to a straight friend; and
5. Disclosure as a sexual minority to a family member.
Consistent with previous research, it found that members of the youngest age cohort (ages 18 to 26) reported the earliest ages of onset for all milestones and the shortest lengths of time between milestones.

Question 12

Older adults with mild neurocognitive disorder due to Alzheimer’s disease would most likely obtain the highest score on the WAIS-IV __________ Index and lowest score on the __________ Index.

A. Verbal Comprehension; Working Memory

B. Working Memory; Perceptual Reasoning

C. Perceptual Reasoning; Processing Speed

D. Verbal Comprehension; Processing Speed

Answer 12

Correct answer

D. Verbal Comprehension; Processing Speed

Explanation
The WAIS-IV Technical and Interpretive Manual (Psychological Corporation, 2008) reports the following mean Index scores for individuals with mild Alzheimer’s disease: Verbal Comprehension 86.2, Perceptual Reasoning 85.8, Working Memory 84.3, and Processing Speed 76.6.

Question 13

A division of labor and a hierarchy of authority are defining characteristics of which of the following organizational theories?

A. Weber’s bureaucracy

B. McGregor’s Theory Y

C. Fiedler’s contingency theory

D. Katz and Kahn’s open-system theory

Answer 13

Correct answer
A. Weber’s bureaucracy

Explanation
As described by Weber (1947), an ideal bureaucracy is characterized by a division of labor, a hierarchy of authority, clearly defined rules and procedures, impersonal relationships based on position, and selection and promotion decisions based on an applicant’s or employee’s technical competence.

Question 14

Cataplexy, hypocretin deficiency, and short rapid eye movement sleep latency are symptoms of:

A. narcolepsy.

B. sleep apnea.

C. temporal lobe seizures.

D. Tourette’s syndrome.

Answer 14

Correct answer
A. narcolepsy.

Explanation
The DSM-5 diagnosis of narcolepsy requires irrepressible episodes of sleep (daytime naps) with at least one of the following: cataplexy, hypocretin deficiency, or REM sleep latency less than or equal to 15 minutes.

Question 16

In a normal distribution, a percentile rank of ____ is one standard deviation above the mean of the distribution.

A. 50

B. 68

C. 84

D. 97

Answer 16

Answer C is correct. A percentile rank is a transformed score that indicates the percentage of scores that fall at or below a given score. In a normal distribution, when an examinee’s percentile rank is 84, this means that his/her score is one standard deviation above the mean.

Question 17

Dr. Oz conducts a study to compare the effects of three treatments (drug, relaxation, and drug plus relaxation) on the systolic blood pressure of patients who have secondary hypertension as the result of three different conditions (tobacco use, chronic alcohol use, or obesity). To analyze the main and interaction effects of treatment and condition on systolic blood pressure, Dr. Oz will use which of the following statistical tests?

A. chi-square test for multiple samples

B. t-test for independent samples

C. two-way ANOVA

D. MANOVA

Answer 17

Answer C is correct. The first two things to do when choosing an inferential statistical test are to identify (1) the independent and dependent variables and (2) the scale of measurement of the dependent variable. This study has two independent variables – treatment and condition – and one dependent variable – systolic blood pressure. You may have had trouble with this question because you were uncertain about the scale of measurement of systolic blood pressure. However, a general rule is that most physical measurements (including systolic blood pressure) represent an interval or ratio scale, which means that the appropriate statistical test will be a t-test or analysis of variance. To choose between the t-test, the two-way ANOVA, and the MANOVA, you have to consider how many independent and dependent variables there are. There are two independent variables, which eliminates the t-test because it’s used when there’s only one independent variable; and there is one dependent variable, which eliminates the MANOVA because it’s used when there are two or more dependent variables. That leaves the two-way ANOVA, which is the correct answer. It’s used when a study includes two independent variables and one dependent variable that’s measured on an interval or ratio scale.

Question 18

When test scores represent an interval or ratio scale and the distribution of scores is skewed, the best measure of central tendency for the distribution is usually which of the following?

A. mode

B. mean

C. median

D. minuend

Answer 18

Answer C is correct. The choice of the appropriate measure of central tendency not only depends on the scale of measurement of the data but also on several other factors including the shape of the data distribution. When the data represent an interval or ordinal scale, the mean is ordinarily the appropriate measure of central tendency. However, when the distribution is skewed, the mean may provide misleading information because its magnitude is affected by the extreme outliers. Consequently, for a skewed distribution, the median is a better measure of central tendency because it’s not affected by the extreme outliers and is more representative of the typical score in the distribution. (The minuend is the first term in a subtraction problem – e.g., 30 in the problem 30 – 10. It’s NOT something you need to be familiar with for the exam.)

Question 19

The size of the standard error of the mean increases as:

A. the population standard deviation increases and the sample size decreases.

B. the population standard deviation decreases and the sample size increases.

C. the population standard deviation and the sample mean both decrease.

D. the population standard deviation and the sample mean both increase.

Answer 19

Answer A is correct. The standard error of the mean is the standard deviation of the sampling distribution of the mean and is calculated by dividing the population standard deviation by the square root of the sample size. Consequently, as the population standard deviation (the numerator) increases and the sample size (the denominator) decreases, the standard error of the mean increases.

Question 20

A research study involves comparing the short- and long-term effects of three brief behavioral treatments for social anxiety disorder by randomly assigning clinic patients who have just received the diagnosis to one of the three treatments and assessing their symptoms before treatment and then one week, four weeks, 12 weeks, and 24 weeks following treatment. Which of the following research designs is being used in this study?

A. counterbalanced

B. mixed

C. between groups

D. within subjects

Answer 20

Answer B is correct. A mixed design is being used when a study has at least two independent variables and one variable is a between groups variable and the other is a within subjects variable. The study described in this question has two independent variables – treatment and time: Treatment is a between subjects variable because each subject will receive only one of the three treatments, while time is a within subjects variable because all subjects will be assessed at five different times.

Question 21

To measure the degree of association between high school diploma (yes or no) and yearly income in dollars, you would use which of the following correlation coefficients?

A. Spearman rho

B. point biserial

C. contingency coefficient

D. eta

Answer 21

Answer B is correct. The point biserial correlation coefficient is the appropriate correlation coefficient when one variable is a true dichotomy and the other is measured on a continuous (interval or ratio) scale. High school diploma (yes or no) is a true dichotomy and yearly income in dollars is measured on a continuous scale.

Question 22

The internal validity of a research study is threatened by statistical regression when:

A. more participants with average scores on the pretest dropped out of the study than did participants with high or low scores.

B. more participants with average scores responded favorably to the independent variable than did other participants.

C. participants were chosen for inclusion in the study because they obtained extremely low scores on a pretest.

D. participants were chosen for inclusion in the study because they obtained average scores on a pretest.

Answer 22

Answer C is correct. Statistical regression refers to the tendency of extremely high and low scores to “regress to the mean” on retesting. It can threaten a study’s internal validity because, when extremely high and low scores become less extreme on retesting, this may be due to statistical regression rather than the effects of the independent variable.

Question 23

You would use the multivariate analysis of variance (MANOVA) to analyze the data you obtain in a research study when:

A. you want to control the effects of an extraneous variable by statistically removing its effects on the dependent variable.

B. you want to measure the main and interaction effects of an extraneous variable on the dependent variable.

C. your study includes at least one between-subjects variable and one within-subjects variable.

D. your study includes two or more dependent variables that are measured on an interval or ratio scale.

Answer 23

Answer D is correct. The MANOVA is used when a study includes one or more independent variables and two or more dependent variables that are each measured on an interval or ratio scale.

Question 24

To determine the correlation between college graduate (yes or no) and yearly income in dollars, you would use which of the following correlation coefficients?

A. phi coefficient

B. Pearson r

C. point biserial coefficient

D. Spearman rho

Answer 24

Answer C is correct. The point biserial correlation coefficient is used when one variable is a true dichotomy (e.g., college graduate or nongraduate) and the other variable is continuous (e.g. yearly income in dollars).

Question 25

For a test that consists of 50 true/false questions, the optimal average item difficulty level (p) is:

A. 1.0

B. .75

C. .50

D. .25

Answer 25

Answer B is correct. The optimal difficulty level for test questions depends on several factors including the chance that examinees can choose the correct answers just by guessing. With regard to this factor, the optimal difficulty level falls halfway between 100% and the probability of choosing the correct answer by guessing: For true/false questions, the probability of guessing correctly is 50%, so the optimal difficulty level is halfway between 1.0 and .50, which is .75.

Question 26

A test has a mean of 60 and standard deviation of 5, and test scores are normally distributed. Based on this information, you can conclude that about 95% of scores fall between scores of:

A. 55 and 65.

B. 50 and 70.

C. 45 and 75.

D. 40 and 80.

Answer 26

Answer B is correct. In a normal distribution about 95% of scores fall between the scores that are plus and minus two standard deviations from the mean. This test has a mean of 60 and standard deviation of 5, so about 95% of scores fall between 60 plus and minus 10 (5 x 2), which is between 50 and 70.

Question 27

To compare the effectiveness of two brief treatments for social anxiety disorder, you obtain a sample of individuals who have received this diagnosis, determine the severity of each subject’s social anxiety, match the subjects in pairs based on the severity of their symptoms, and randomly assign one member of each pair to one of the treatments and other member to the other treatment. To compare the scores subjects in the two groups receive on a measure of symptom severity after they receive treatment, you will use which of the following?

A. t-test for correlated samples

B. t-test for uncorrelated samples

C. two-way ANOVA

D. single-sample chi-square test

Answer 27

Answer A is correct. The first steps in identifying the appropriate statistical test are to identify the independent and dependent variables and the scale of measurement of the dependent variable. This study’s independent variable is type of treatment and the dependent variable is score on a measure of severity of anxiety following treatment. More specifically, the dependent variable is score on a measure of symptom severity and, for the exam, you can assume that scores represent an interval or ratio scale. This means that a statistical test will be used to compare the mean scores obtained by two groups. The t-test and two-way ANOVA are both used to compare mean scores but, because there are only two means, the t-test is the appropriate test. To determine which t-test to use, you determine how the means were obtained: In this study, they were obtained from related groups (from groups that consist of subjects who were matched in terms of initial symptom severity). The t-test for correlated samples is the appropriate test when two means are obtained from the same group or from two groups that are related in some way.

Question 28

To evaluate the effectiveness of a stress reduction technique for alleviating test anxiety, a psychologist administers a measure of test anxiety to Psychology 101 undergraduates, chooses the 50 students with the highest scores on the test, administers the intervention to the students, and then readministers the measure of test anxiety. The biggest threat to this study’s internal validity is:

A. differential selection

B. reactivity

C. statistical regression.

D. instrumentation

Answer 28

Answer C is correct. Whenever subjects are chosen for inclusion in a study because they have extreme scores on the pretest, their scores on the posttest are likely to “regress toward the mean” regardless of the effects of the independent variable. This is referred to as statistical regression, and it threatens a study’s internal validity whenever it’s not possible to ascertain to what extent a change in posttest scores is due to statistical regression or the effects of the independent variable.

Question 29

You would use which of the following statistical tests to compare the number of adults living in a rural, urban, or suburban community who have received a diagnosis of a bipolar disorder, depressive disorder, or anxiety disorder?

A. single-sample chi-square test

B. multiple-sample chi-square test

C. one-way ANOVA

D. factorial ANOVA

Answer 29

You would use which of the following statistical tests to compare the number of adults living in a rural, urban, or suburban community who have received a diagnosis of a bipolar disorder, depressive disorder, or anxiety disorder?

A. single-sample chi-square test

B. multiple-sample chi-square test

C. one-way ANOVA

D. factorial ANOVA

Question 30

A psychologist finds that the relationship between physiological arousal and motor performance for a sample of athletes is .40. This means that ___% of variability in motor performance is explained by variability in physiological arousal.

A. 60

B. 40

C. 36

D. 16

Answer 30

Answer D is correct. A correlation coefficient between two different variables can be squared to calculate the coefficient of determination, which indicates the amount of variability in one variable that’s explained by variability in the other variable. The psychologist obtained a correlation of .40 between arousal and motor performance, and .40 squared is .16. This means that 16% of variability in motor performance is explained by variability in arousal.

Question 31

Which of the following best describes the variables included in a structural equation model?

A. Manifest variables cannot be observed directly, and their influence is inferred from indicator variables.

B. Latent variables cannot be observed directly, and their influence is inferred from indicator variables.

C. Manifest and latent variables cannot be observed directly, and their influence is inferred from indicator variables.

D. Manifest variables cannot be observed directly, and their influence is inferred from latent variables.

Answer 31

Answer B is correct. In structural equation modeling, observed variables are also known as manifest variables and indicators and are directly observed and measured. Latent variables are also known as factors and constructs and cannot be directly observed or measured but are inferred from observed variables.

Question 32

You would use stepwise multiple regression when you want to:

A. identify the fewest number of predictors needed to make accurate predictions about scores on a criterion.

B. identify the fewest number of predictors needed to accurately categorize people into two or more mutually exclusive criterion groups.

C. identify the predictors that have a causal relationship with the criterion.

D. identify the optimal number of criterion groups.

Answer 32

Answer A is correct. Stepwise multiple regression involves adding or subtracting one predictor at a time to the multiple regression equation in order to identify the fewest number of predictors that are needed to make accurate predictions about scores on the criterion.

Question 33

Which of the following is the appropriate technique for using measures of severity of depression, anxiety, drug/alcohol use, and cognitive impairment to classify individuals with major depressive disorder as being at risk or not at risk for suicide?

A. regression analysis

B. multiple regression

C. canonical correlation

D. discriminant function analysis

Answer 33

Answer D is correct. Discriminant function analysis is the appropriate multivariate technique when two or more predictors will be used to estimate status on one nominal (grouping) variable.

Question 34

For a sample of middle school students with high IQs, the correlation between IQ scores and achievement test scores is .35. If the correlation between IQ scores and achievement test scores is calculated for a sample of middle school students whose IQs represent the full range of IQ scores, the correlation coefficient is likely to be:

A. .35

B. larger than .35.

C. smaller than .35.

D. smaller or larger than .35

Answer 34

Answer B is correct. The scores used to obtain the original correlation coefficient had a restriction in range because the sample included only students with high IQs. A restricted range of scores tends to lower the correlation coefficient, so recalculating the coefficient for students with an unrestricted range is likely to produce a larger correlation coefficient.

Question 35

To determine the relationship between cigarette smoking and absence from work, Dr. Nunez obtains a sample of employees who are either smokers or nonsmokers and determines the number of days each employee was absent from work the previous year. Dr. Nunez will use which of the following to calculate the correlation between these two variables?

A. Pearson r

B. Spearman rho

C. point biserial coefficient

D. contingency coefficient

Answer 35

Answer C is correct. The point biserial coefficient is used when one variable is a true dichotomy (smokers versus nonsmokers) and the other is continuous (number of days absent from work). (A useful mnemonic for distinguishing between the point biserial and biserial coefficients is to use the “t” in point as a reminder that the point biserial coefficient is used when one variable is a true dichotomy.)

Question 36

Bayes’ theorem allows researchers to update prior knowledge about a parameter using:

A. current (observed) data.

B. previous knowledge and current (observed) data.

C. qualitative information.

D. a revised theoretical framework.

Answer 36

Answer B is correct. Bayes’ theorem uses previous knowledge (the prior) and current data (the likelihood function) to derive updated knowledge about a parameter (the posterior).

Question 37

The probability of making a Type II error equals which of the following?

A. alpha

B. beta

C. one minus alpha

D. one minus beta

Answer 37

Answer B is correct. The probability of making a Type II error is equal to beta which is not set by the researcher but can be reduced by increasing statistical power.

Question 38

Statistical power refers to the ability to:

A. retain a null hypothesis.

B. retain a true null hypothesis.

C. reject a null hypothesis.

D. reject a false null hypothesis.

Answer 38

Answer D is correct. Statistical power refers to the ability to reject a false null hypothesis, which is ordinarily what a researcher wants to do.

Question 39

To calculate the standard error of means you need which of the following?

A. sample mean and standard deviation

B. sample mean and sample size

C. population standard deviation and sample size

D. population mean and standard deviation

Answer 39

Answer C is correct. The central limit theorem predicts that the standard deviation of the sampling distribution (also known as the standard error of means) is equal to the population standard deviation divided by the square root of the sample size.

Question 40

Changing alpha from .05 to .01:

A. increases the probability of making a Type I error and decreases the probability of making a Type II error.

B. decreases the probability of making a Type I error and increases the probability of making a Type II error.

C. increases the probability of making a Type I error and Type II error.

D. decreases the probability of making a Type I error and Type II error.

Answer 40

Answer B is correct. Knowing that changing the size of alpha has opposite effects on the chance of making a Type I and Type II error would have allowed you to eliminate answers C and D. Then knowing that a Type I error occurs when a true null hypothesis is rejected and that decreasing alpha makes it harder to reject a null hypothesis whether it is true or false would have helped you identify answer B as the correct answer: Decreasing alpha decreases the probability of making a Type I error (rejecting a true null hypothesis) and, conversely, increases the probability of making a Type II error (retaining a false null hypothesis).

Question 41

The central limit theorem predicts that the sampling distribution of means increasingly approaches normal as the:

A. number of samples increases regardless of the shape of the population distribution.

B. size of the sample increases regardless of the shape of the population distribution.

C. number of samples increases only when the population distribution is normal.

D. size of the sample increases only when the population distribution is normal.

Answer 41

Answer B is correct. The central limit theorem predicts that the sampling distribution of means increasingly approaches a normal shape as the size of the sample increases, regardless of the shape of the population distribution of scores.

Question 42

A Type I error occurs when a researcher:

A. retains a true null hypothesis.

B. retains a false null hypothesis.

C. rejects a true null hypothesis.

D. rejects a false null hypothesis.

Answer C is correct. When a researcher rejects a true null hypothesis, the researcher has concluded that the independent variable has had a significant effect on the dependent variable, but the observed effect is actually due to sampling error or other factors. This type of incorrect decision is known as a Type I error.

Answer 42

Answer C is correct. When a researcher rejects a true null hypothesis, the researcher has concluded that the independent variable has had a significant effect on the dependent variable, but the observed effect is actually due to sampling error or other factors. This type of incorrect decision is known as a Type I error.

Question 43

When a predictor included in a multiple regression equation has a negative beta weight, this means that:

A. The predictor has a negative correlation with the other predictors.

B. The predictor has a negative correlation with the criterion.

C. The predictor has a statistically significant relationship with the criterion.

D. The predictor does not have a statistically significant relationship with the criterion.

Answer 43

Answer B is correct. Beta weights are standardized regression coefficients, and a predictor’s beta weight indicates the strength of the relationship between the predictor and the criterion. When a predictor’s beta weight is positive, this means there’s a positive relationship between the predictor and criterion (i.e., as scores on the predictor increase, scores on the criterion increase). Conversely, when the beta weight is negative, this means there’s a negative relationship between the predictor and criterion (i.e., as scores on the predictor increase, scores on the criterion decrease).

Question 45

A psychologist conducts a study to evaluate the effects of three different work shifts (day, swing, and graveyard) on the average number of errors, absences, and accidents of assembly line workers during a six-month period. To minimize the probability of making a Type I error, the psychologist will use which of the following to analyze the data she collects?

A. one-way ANOVA

B. three-way ANOVA

C. ANCOVA

D. MANOVA

Answer 45

Answer D is correct. The MANOVA (multivariate analysis of variance) is used when a study includes one or more independent variables and two or more dependent variables that are each measured on an interval or ratio scale. An advantage of conducting a single MANOVA rather than separate ANOVAs for each dependent variable is that doing so reduces the probability of making a Type I error – i.e., it reduces the experimentwise error rate. The study described in this question has one independent variable (work shift) and three dependent variables that are all measured on a ratio scale (number of errors, absences, and accidents). Therefore, the MANOVA can be used to analyze the data collected in this study.

Question 47

A researcher conducts a study to determine if there are gender differences in acceptance as a graduate student into the six largest departments at a university. To analyze the data she collects in this study, the researcher will use which of the following?

A. one-way ANOVA

B. two-way ANOVA

C. single-sample chi-square test

D. multiple-sample chi-square test

Answer 47

Answer D is correct. The first and second steps in identifying the appropriate statistical test are identifying the study’s independent and dependent variables and the scale of measurement of the dependent variable. This study has two variables – gender and department – and gender can be viewed as the independent variable and department as the dependent variable. The dependent variable – department – is a nominal variable. The chi-square test is the appropriate test for analyzing nominal data and, when a study has two or more variables, the multiple-sample chi-square test is used. Keep in mind that, for the chi-square test, you count the total number of variables regardless of whether they’re independent or dependent variables: The multiple-sample chi-square test is used when the study has two or more variables, and the single-sample chi-square test is used when a study is a descriptive study and has only one variable.

Question 49

The scores obtained by 35 students on a math exam and a physics exam are converted to ranks. To determine the degree of association between the two sets of ranks, the appropriate correlation coefficient is which of the following?

A. biserial

B. point biserial

C. Spearman

D. Pearson

Answer 49

Answer C is correct. Knowing that “Spearman” refers to the Spearman rank-order correlation coefficient would have helped you identify the correct answer to this question. As its name suggests, it’s used to determine the correlation between rank-ordered data.