Statistics And Research Design - Domain Quiz Flashcards
A research participant is instructed to “think aloud” while solving complex geometry problems in order to identify the thought processes that underlie successful and unsuccessful problem-solving. The participant’s verbalizations will be recorded and analyzed. This technique is known as:
Select one:
a. event sampling.
b. protocol analysis.
c. situational sampling.
d. sequential analysis.
In this situation, information about the participant’s cognitive processes is being obtained.
Answer B is correct: Protocol analysis is also referred to as the “think aloud” exercise and is used to obtain information about cognitions associated with a particular type of problem or other phenomenon.
Answer A is incorrect: Event sampling is a type of behavioral sampling that involves observing and recording information about a behavior when it occurs (e.g., observing a conflict between group therapy members).
Answer C is incorrect: Situational sampling involves observing a behavior in multiple settings.
Answer D is incorrect: Sequential analysis is used to encode behavioral sequences and is useful for studying complex social behaviors.
The correct answer is: protocol analysis.
Cluster sampling involves:
Select one:
a. randomly selecting individuals from pre-defined groups in the population that are relevant to the research hypothesis.
b. randomly selecting individuals who have been identified as belonging to the target groups.
c. randomly selecting pre-existing groups of individuals from the population.
d. randomly assigning pre-existing groups to different levels of the independent variable.
As its name suggests, cluster sampling involves selecting clusters (groups) of individuals from the population.
Answer C is correct: When using cluster sampling, pre-existing groups are randomly selected from the population (e.g., schools, mental health clinics) and all individuals in each group or a random sample of participants in each group are included in the study.
Answer A is incorrect: This answer describes stratified random sampling.
Answer B is incorrect: See explanation for Answer C.
Answer D is incorrect: See explanation for Answer C.
The correct answer is: randomly selecting pre-existing groups of individuals from the population.
Interval recording is most useful for:
Select one:
a. studying behaviors that have no fixed beginning or end.
b. studying behaviors that have a long duration.
c. obtaining a detailed narrative description of a behavior.
d. identifying the antecedents and consequences of a behavior.
Interval recording is a method for sampling and recording the frequency of a behavior.
Answer A is correct: Interval recording is a type of time sampling that involves recording whether or not a behavior occurred during each interval of time. It is useful for behaviors that have no clear beginning or end.
The correct answer is: studying behaviors that have no fixed beginning or end.
Scores on an extraneous variable:
Select one:
a. correlate with scores on the dependent variable.
b. correlate with scores on the independent variable.
c. correlate with scores on the dependent and independent variables.
d. do not correlate with scores on the dependent or independent variable.
By definition, an extraneous variable correlates with (has a systematic effect) on the dependent variable.
Answer A is correct: Extraneous variables are irrelevant to the purpose of a research study but confound its results because they correlate with the dependent variable, which makes it difficult to identify the effects of the independent variable on the dependent variable. Additional information about extraneous variables is provided in the Statistics and Research Design chapter of the written study materials.
The correct answer is: correlate with scores on the dependent variable.
The primary characteristic that distinguishes true experimental research from quasi-experimental research is that, in the former:
Select one:
a. participants are randomly selected from the population.
b. participants are randomly assigned to treatment groups.
c. the levels of the independent variable are systematically selected.
d. a parametric statistical test can be used to analyze the data.
Answer B is correct: For the exam, you want to be sure you understand the difference between random selection (sampling) and random assignment so that you can answer questions like this one. The “hallmark” of true experimental research is the ability to randomly assign participants to treatment groups, which helps ensure that groups do not differ in a systematic way at the beginning of the study.
Answer A is incorrect: See explanation for Answer B.
Answer C is incorrect: In some cases, levels of the IV may also be “systematically selected” in quasi-experimental research.
Answer D is incorrect: The choice of a parametric or nonparametric statistical test depends on the nature of the data, not the type of study.
The correct answer is: participants are randomly assigned to treatment groups.
To assess the effects of a stimulus control procedure on eating behaviors, Dr. Barry Buvette obtains a sample of 20 overweight females and 20 overweight males and determines their average daily caloric intake and satisfaction with their food consumption during the seven days before and seven days after training in the procedure. The dependent variable(s) in this study is or are:
Select one:
a. stimulus control procedure.
b. stimulus control procedure and gender.
c. caloric intake.
d. caloric intake and satisfaction with food consumption.
In this study, the researcher is investigating the effects of the self-control procedure and gender on caloric intake and satisfaction with food consumption.
Answer D is correct: This study has two dependent variables – caloric intake and satisfaction with food intake. See the Statistics and Research Design chapter for information on independent and dependent variables and how to distinguish between them.
Answer A is incorrect: See explanation for Answer D.
Answer B is incorrect: Stimulus control procedure and gender are both independent variables in this study.
Answer C is incorrect: See explanation for Answer D.
The correct answer is: caloric intake and satisfaction with food consumption.
When using the technique known as blocking:
Select one:
a. an extraneous variable is “held constant.”
b. the effects of an extraneous variable are statistically removed.
c. an extraneous variable is treated as an independent variable.
d. an extraneous variable is treated as a dependent variable.
Answers A, B, and C all describe methods for controlling an extraneous variable but only one describes the method known as blocking. Additional information about controlling extraneous variables is provided in the Statistics and Research Design chapter of the written study materials.
Answer C is correct: This answer describes blocking which allows a researcher to evaluate the main and interaction effects of the extraneous variable.
Answer A is incorrect: Holding the extraneous variable constant is one method of control but this is not referred to as blocking.
Answer B is incorrect: This is another way to control an extraneous variable but is not referred to as blocking.
Answer D is incorrect: When using blocking, the extraneous variable is treated like an independent (not dependent) variable.
The correct answer is: an extraneous variable is treated as an independent variable.
An interviewer unintentionally nods whenever research participants answer his questions in ways that confirm the study’s research hypothesis. The interviewer’s behavior is best described as an example of which of the following?
Select one:
a. demand characteristics
b. Hawthorne effect
c. halo effect
d. instrumentation
Experimenter expectancy is the term used to describe the ways in which an experimenter may bias the result of a research study.
Answer A is correct: In the situation described in this question, the interviewer’s expectancies are acting as a source of demand characteristics – i.e., the interviewer is giving information to participants that lets them know what behavior is expected of them.
The correct answer is: demand characteristics
A psychologist evaluates the effects of a 15-month training program on the conservation skills of preoperational children by administering a measure of conservation to the same group of children before and at the end of training. The psychologist finds that significantly more children are able to conserve after the program than before the program. The biggest threat to this study’s internal validity is:
Select one:
a. maturation.
b. history.
c. instrumentation.
d. statistical regression.
For the exam, you want to be familiar with all of the threats listed in the answers to this question. Information about them is provided in the Statistics and Research Design chapter of the written study materials.
Answer A is correct: In the situation described in this question, any change in ability to conserve could be due to normal development (maturation) over the 15-month period rather than to the effects of the training program.
The correct answer is: maturation.
A psychologist obtains a statistically significant F-ratio for the interaction between two independent variables (IVs). This means that:
Select one:
a. the effects of one IV are significant across all levels of the second IV.
b. the effects of one IV are contingent on the level of the second IV.
c. the main effects of both IVs are statistically significant.
d. the effects of the two IVs are statistically significant only when they are considered jointly.
Answer B is correct: This answer is another way of saying that the effects of one IV are different at different levels of the other IV, which is the definition of an interaction.
The correct answer is: the effects of one IV are contingent on the level of the second IV.
As applied to research design, “external validity” refers to which of the following?
Select one:
a. accuracy
b. control
c. significance
d. generalizability
Both internal and external validity are concerns in the design of research. Internal validity refers to the extent to which it can be assumed that the changes in the dependent variable are caused by the independent variable. External validity refers to the extent to which the results of a research study can be generalized.
Answer D is correct: External validity refers to the researcher’s ability to generalize research findings beyond the specific time, setting, and participants involved in the research study.
The correct answer is: generalizability
Dr. Angela Angst is using a repeated measures design to compare the effects of different techniques for reducing free-floating anxiety. To control potential carryover effects, Dr. Angst should use which of the following?
Select one:
a. an unobtrusive measure
b. blocking
c. counterbalancing
d. a cross-sequential design
Carryover effects occur when being exposed to one level of the independent variable affects how a participant reacts to another level of that variable. It is a potential threat to the validity of repeated measures designs in which each participant is exposed to more than one level of the independent variable.
Answer C is correct: Counterbalancing controls carryover effects by presenting the different levels of the independent variable to different participants in a different order.
The correct answer is: counterbalancing
In which of the following types of research studies do participants act as their own “controls”?
Select one:
a. cross-sectional
b. factorial
c. analogue
d. single-subject
For participants to act as their own controls, each participant would have to participate in both treatment and no-treatment groups. This occurs in only one of the designs listed in the answers.
Answer D is correct: All single-subject designs include at least one baseline (no treatment) phase and one treatment phase. Consequently, when using a single-subject design, a participant acts as his or her own no-treatment control (i.e., the participant’s status on the dependent variable is compared before and after the treatment is applied).
The correct answer is: single-subject
The Solomon four-group design is used to control which of the following threats to the validity of a research study?
Select one:
a. statistical regression
b. pretest sensitization
c. reactivity
d. maturation
When using the Solomon four-group design, the pretest is treated as an additional independent variable so that its effects on the dependent variable can be statistically analyzed.
Answer B is correct: When using the Solomon four-group design, the effects of administering a pretest on the study’s internal and external validity can be identified.
The correct answer is: pretest sensitization
According to the Central Limit Theorem, the shape of the sampling distribution of means:
Select one:
a. is always normal.
b. is normal only when the population distribution of scores is normal.
c. approaches normal as the number of samples increases regardless of the shape of the population distribution of scores.
d. approaches normal as the size of the samples increases regardless of the shape of the population distribution of scores.
For the exam, you want to be familiar with the three predictions made by the Central Limit Theorem about the sampling distribution. These are discussed in the Statistics and Research Design chapter of the written study materials.
Answer D is correct: The Central Limit Theorem predicts that the sampling distribution increasingly approaches normal as the sample size (not the number of samples) increases.
The correct answer is: approaches normal as the size of the samples increases regardless of the shape of the population distribution of scores.
A researcher will use trend analysis to analyze the data she has collected in a research study when:
Select one:
a. the research design is quasi-experimental.
b. the dependent variables are correlated.
c. the independent variable is quantitative.
d. the research design is longitudinal.
For the exam, you want to be familiar with trend analysis as well as with the other forms of the ANOVA that are described in the written study materials.
Answer C is correct: Trend analysis is a type of analysis of variance that can be used when the independent variable is quantitative. It allows the researcher to determine whether there is a significant linear or nonlinear effect of the independent variable on the dependent variable.
The correct answer is: the independent variable is quantitative.
A researcher would use a multivariate analysis of variance (MANOVA) to analyze the data she collects in a study when:
Select one:
a. the study includes one or more independent variables and two or more dependent variables.
b. the study includes three or more independent variables and a single dependent variable.
c. she wants to statistically remove the effects of an extraneous variable.
d. she wants to statistically analyze the main and interaction effects of an extraneous variable.
The MANOVA is used when a study includes two or more dependent variables.
Answer A is correct: When all dependent variables are measured on an interval or ratio scale, a researcher can use the MANOVA rather than separate ANOVAs to evaluate the effects of the independent variable on the dependent variables. Doing so helps reduce the experimentwise error rate.
Answer B is incorrect: A factorial ANOVA would probably be the appropriate test in this situation if the dependent variable is measured on an interval or ratio scale.
Answer C is incorrect: The ANCOVA is used to statistically remove the effects of an extraneous variable.
Answer D is incorrect: The randomized block ANOVA is used to statistically analyze the effects of an extraneous variable when that variable is being treated as an independent variable.
The correct answer is: the study includes one or more independent variables and two or more dependent variables.
Dr. Terry Tas obtains SAT scores from a sample of 30 high school seniors following their participation in a workshop designed to improve SAT scores. The appropriate statistical test for comparing the mean score obtained by these students to the national mean is which of the following?
Select one:
a. t-test for a single sample
b. t-test for independent samples
c. one-way ANOVA
d. Wilcoxon test
The analysis of the data collected in this study will involve comparing a sample mean to a known population mean.
Answer A is correct: The different forms of the t-test are all used to compare two means, and the t-test for a single sample is used when a sample mean will be compared to a known population mean.
Answer B is incorrect: The t-test for independent samples is used to compare means obtained from two independent groups (samples).
Answer C is incorrect: The one-way ANOVA is used to compare means obtained from two or more independent groups.
Answer D is incorrect: The Wilcoxon Matched-Pairs test is used to compare the ranks obtained from two correlated (matched) groups.
The correct answer is: t-test for a single sample
The standard error of the mean (SEM) decreases as:
Select one:
a. the population standard deviation increases and the sample size increases.
b. the population standard deviation increases and the sample size decreases.
c. the population standard deviation decreases and the sample size decreases.
d. the population standard deviation decreases and the sample size increases.
Knowing the formula for the standard error of the mean would have helped you identify the correct answer to this question.
Answer D is correct: The standard error of the mean is equal to the population standard deviation divided by the square root of the sample size. Plugging numbers into this formula proves that the standard error decreases in size as the population standard deviation (numerator) decreases and or or the sample size (denominator) increases. See the Statistics and Research Design chapter of the written study materials for examples of the effects of changing the standard deviation and sample size on the size of the standard error of the mean.
The correct answer is: the population standard deviation decreases and the sample size increases.
Ninety adults are randomly assigned to one of three groups and the average IQ score of each group is calculated. If a one-way ANOVA is used to compare the mean IQ scores of the three groups, you would expect the resulting F-ratio to be:
Select one:
a. equal to 0.
b. equal to 1.0.
c. greater than 100.
d. equal to -1.0
The F-ratio is calculated by dividing a measure of variability due to error plus treatment (mean square between) by a measure of variability due to error only (mean square within).
Answer B is correct: When there are no treatment effects (which would be the case in the situation described in this question), the numerator and denominator should both be measures of error and the F-ratio will simply be error divided by error, which should equal a value very close to 1.0.
The correct answer is: equal to 1.0.
The chi-square test would NOT be the appropriate test for analyzing data collected from which of the following studies?
Select one:
a. a study conducted to determine if there is a difference in the number of males and females who either support, do not support, or have no opinion about gun legislation
b. a study conducted to compare the number of males and females who say they prefer paper, plastic, or hemp bags for their groceries before and after they view a film on recycling
c. a study conducted to determine if there is any difference in the proportion of people who have received a diagnosis of Bipolar Disorder - Mixed, Bipolar Disorder - Manic, or Bipolar Disorder - Depressed who have either one parent, both parents, or neither parent with an Affective Disorder
d. a study conducted to compare the number of shoppers who say they prefer one of four different cleaning products
The chi-square test is used when the data to be analyzed represent a nominal scale of measurement (i.e., the frequencies in each nominal category will be compared) and when certain assumptions are met.
Answer B is correct: One of the assumptions for the chi-square test is independence of observations. In the study described in this answer, the preferences of each participant will be determined twice (before and after viewing the film) and, consequently, the assumption of independence is violated.
Answer A is incorrect: The multiple-sample chi-square test would be the appropriate test for analyzing data collected in this study.
Answer C is incorrect: The multiple-sample chi-square test would be the appropriate test for analyzing the data collected in this study.
Answer D is incorrect: The single-sample chi-square test would be the appropriate test for the study described in this answer.
The correct answer is: a study conducted to compare the number of males and females who say they prefer paper, plastic, or hemp bags for their groceries before and after they view a film on recycling
The t-test for dependent samples is used to analyze the data collected in a study involving 36 participants who had been matched on an extraneous variable before being assigned to one of the two treatment groups. The degrees of freedom for this study are:
Select one:
a. 36
b. 35
c. 18
d. 17
The degrees of freedom for the t-test for dependent (correlated) samples is equal to N - 1, where N is the number of pairs of scores.
Answer D is correct: In this study, there are 18 pairs of scores, so the degrees of freedom are (18 - 1), or 17.
The correct answer is: 17
The t-test for dependent samples is used to analyze the data collected in a study involving 36 participants who had been matched on an extraneous variable before being assigned to one of the two treatment groups. The degrees of freedom for this study are:
Select one:
a. 36
b. 35
c. 18
d. 17
The degrees of freedom for the t-test for dependent (correlated) samples is equal to N - 1, where N is the number of pairs of scores.
Answer D is correct: In this study, there are 18 pairs of scores, so the degrees of freedom are (18 - 1), or 17.
The correct answer is: 17
For children with ADHD, an academic achievement test has a mean of 40 and a standard deviation of 8. Assuming that the distribution of scores is normally shaped, you can conclude that 16% of these children obtained scores below a score of:
Select one:
a. 24
b. 32
c. 40
d. 48
For the exam, you want to be familiar with the areas under the normal curve so that you can answer questions like this one.
Answer B is correct: In a normal distribution the score that is one standard deviation below the mean divides the distribution so that 16% of cases fall below that score and the remaining 84% fall above it. In this distribution, a score of 32 is one standard deviation below the mean.
The correct answer is: 32
In a leptokurtic distribution:
Select one:
a. scores are distributed more evenly throughout the distribution than they are in a normal (mesokurtic) distribution.
b. a larger proportion of scores are located in the middle of the distribution than they are in a normal (mesokurtic) distribution.
c. most scores are in the negative side of the distribution and the tail is extended on the positive side.
d. most scores are in the positive side of the distribution and the tail is extended on the negative side.
For the exam, you want to know the difference between leptokurtic and platykurtic distributions and between positively and negatively skewed distributions. These are described and illustrated in the Statistics and Research Design chapter of the written study materials.
Answer B is correct: A leptokurtic distribution is more “peaked” than the normal distribution – i.e., more scores are located in the middle of the distribution.
Answer A is incorrect: A platykurtic distribution is flatter than the normal distribution – i.e., scores are more evenly distributed throughout the distribution.
Answer C is incorrect: In a positively skewed distribution, most scores are in the negative side and the tail is extended on the positive side by the presence of a few high scores.
Answer D is incorrect: In a negatively skewed distribution, most scores are in the positive side and the tail is extended on the negative side by the presence of a few low scores.
The correct answer is: a larger proportion of scores are located in the middle of the distribution than they are in a normal (mesokurtic) distribution.
In a negatively skewed distribution of scores:
Select one:
a. the median is greater than the mean.
b. the median is less than the mean.
c. the mean is greater than the mode.
d. the median is greater than the mode.
For the exam, you want to be familiar with the relationships between the mean, median, and mode in skewed distributions. These relationships are illustrated in figures included in the Statistics and Research Design chapter of the written study materials.
Answer A is correct: In a negatively skewed distribution, most scores are “piled up” in the positive tail while a relatively few scores are in the negative tail. Because the mean is more sensitive to the magnitude of all scores, it is affected more by the low scores in the negative tail and is lower in value than the median or the mode. Therefore, the median is greater than the mean in a negatively skewed distribution.
Answer B is incorrect: The median is less than the mean in a positively skewed distribution.
Answer C is incorrect: In a negatively skewed distribution, the median is greater than the mean and the mode is greater than the median.
Answer D is incorrect: The median is greater than the mode in a positively skewed distribution.
The correct answer is: the median is greater than the mean.
To be able to conclude that one research participant has twice as much of a characteristic than another participant, your measure of that characteristic must produce scores that represent which scale of measurement?
Select one:
a. ordinal
b. interval
c. ratio
d. nominal
The four scales of measurement differ with regard to the type of information they provide and the kinds of mathematical operations they permit.
Answer C is correct: The ratio scale provides the greatest information. Because it has an absolute zero point, you can conclude that one score is twice as much as another – for example, that a person who weighs 100 pounds weighs twice as much as a person who weighs 50 pounds.
Answer A is incorrect: An ordinal scale divides observations into categories and provides information on the order of those categories. Ranking people in terms of weight is an example of an ordinal scale. When people are ranked in terms of weight, you know that the person with a higher ranking weighs more than a person with a lower ranking but you don’t know the actual difference in their weights.
Answer B is incorrect: An interval scale provides more information than an ordinal scale – i.e., when using an interval scale, you know that the difference between scores of 40 and 45 is the same as the difference between scores of 80 and 85. However, because an interval scale does not have an absolute zero point, you can’t conclude that 80 is twice as much as 40.
Answer D is incorrect: A nominal scale only divides variables into categories and provides no information about the order of those categories (e.g., gender, DSM diagnosis, place of birth).
The correct answer is: ratio
A high school counselor uses a battery of tests to help high school juniors and seniors choose a college major. Which of the following multivariate techniques would be most helpful in this situation?
Select one:
a. multiple regression
b. path analysis
c. discriminant function analysis
d. canonical correlation
For the exam, you want to be familiar with all of the multivariate techniques listed in the responses so that you can answer questions like this one. These techniques and others that you want to be familiar with are described in the written study materials.
Answer C is correct: Discriminant function analysis is used to predict or estimate a person’s status on a single nominal criterion from two or more predictors.
Answer A is incorrect: Multiple regression is used to predict status on a single continuous criterion from scores on two or more predictors.
Answer B is incorrect: Path analysis is a causal modeling technique that is an extension of multiple regression and is used to test a theory about the causal relationships among a set of variables.
Answer D is incorrect: Canonical correlation is the appropriate technique when two or more predictors will be used to predict status on two or more continuous criteria.
The correct answer is: discriminant function analysis
Eta is used to:
Select one:
a. determine the correlation for two variables that are both measured on a nominal scale.
b. determine the correlation for two variables that have a nonlinear relationship.
c. determine if the relationship between three or more variables is statistically significant.
d. determine the degree of association between two or more continuous variables.
Eta is one of several correlation coefficients that you want to be familiar with for the licensing exam.
Answer B is correct: Eta is used to determine the degree of association between two continuous variables when their relationship is nonlinear.
The correct answer is: determine the correlation for two variables that have a nonlinear relationship.
The correlation coefficient for Test A and Test B is -.40. This means that ___% of variability in Test A scores is shared in common with Test B scores.
Select one:
a. 16
b. 40
c. 60
d. 84
Shared variability is one way to interpret the correlation coefficient for two variables.
Answer A is correct: A measure of shared variability is obtained by squaring the correlation coefficient: -.40 squared is .16. Therefore, 16% of variability in Test A scores is shared with (or accounted for by) variability in Test B scores.
The correct answer is: 16
To determine the degree of association between gender and attitude toward abortion when the attitude measure represents an interval scale, you would use which of the following correlation coefficients?
Select one:
a. point biserial
b. Pearson r
c. phi coefficient
d. contingency coefficient
For the exam, you want to be familiar with the use of each of the correlation coefficients listed in the answers to this question.
Answer A is correct: The point biserial coefficient is the appropriate coefficient when one variable represents a true dichotomy and the other is measured on an interval or ratio (continuous) scale. Although gender is not binary, questions on the EPPP may still refer to gender as a dichotomous variable, especially within the statistics questions.
Answer B is incorrect: The Pearson r is the appropriate correlation coefficient when both variables are measured on an interval or ratio scale.
Answer C is incorrect: The phi coefficient is used when both variables are true dichotomies.
Answer D is incorrect: The contingency coefficient is used to determine the degree of association between two nominal variables.
The correct answer is: point biserial
When using path analysis, you are:
Select one:
a. employing two or more predictors to estimate status on a single continuous criterion.
b. employing two or more predictors to predict status on a single nominal criterion.
c. confirming a model involving one-way causal flow between a set of observed variables.
d. developing a model involving one- and two-way causal flow between a set of observed variables and latent traits.
Path analysis is a causal modeling technique that is used to test the veracity of a causal theory or model.
Answer C is correct: One restriction when using path analysis is that the paths must all involve a one-way causal flow.
Answer A is incorrect: See explanation for Answer C.
Answer B is incorrect: See explanation for Answer C.
Answer D is incorrect: LISREL is more complex than path analysis and not only includes two-way paths but also takes into account both observed variables and the latent traits those variables are believed to measure.
The correct answer is: confirming a model involving one-way causal flow between a set of observed variables.
A researcher reports that she calculated a Cohen’s d of .50 for the data she collected in a study that compared two brief treatments for generalized anxiety disorder. This means that:
Select one:
A. there was a difference of one-half standard deviation between the means of the two groups.
B. there was a difference of one-fourth standard deviation between the means of the two groups.
C. the percent of variance accounted for by the difference in treatments was 50%.
D. the percent of variance accounted for by the difference in treatments was 25%.
Cohen’s d is a measure of effect size. It indicates the difference between the means of two groups in terms of standard deviations. Additional information about methods for calculating an effect size is provided in the Statistics and Research Design chapter of the written study materials.
a. CORRECT A Cohen’s d of .50 indicates that one group obtained a mean that is one-half standard deviation higher than the mean obtained by the other group.
b. Incorrect See explanation for response a.
c. Incorrect See explanation for response a.
d. Incorrect See explanation for response a.
The correct answer is: there was a difference of one-half standard deviation between the means of the two groups.
An investigator would use the split-plot ANOVA to analyze the data he has collected for which of the following studies?
Select one:
A. a study in which each participant receives only one level of Variable A and one level of Variable B
B. a study in which participants who received level 1 of Variable A also received either level 1 or 2 of Variable B, while participants who received level 2 of Variable A received either level 3 or 4 of Variable B
C. a study in which each participant received all levels of Variable A but in a different order
D. a study in which each participant received only one level of Variable A but all levels of Variable B
Split-plot is another name for “mixed”; and a researcher would use a split-plot ANOVA when the study uses a mixed design - i.e., it includes both between-groups and within-subjects comparisons.
a. Incorrect This answer describes a study that includes two between-groups variables.
b. Incorrect This answer describes a nested design.
c. Incorrect This answer describes a counterbalanced design with a single independent variable.
d. CORRECT This is the only answer that describes a mixed design: Variable A is a between-groups variable, while Variable B is a within-subjects variable. Additional information about between-groups and within-subjects designs is provided in the Statistics and Research Design chapter of the written study materials.
The correct answer is: a study in which each participant received only one level of Variable A but all levels of Variable B
LISREL (linear structural relations analysis) would be the appropriate method of analysis if your causal model:
Select one:
A. includes measured (observed) attributes only.
B. includes latent traits only.
C. includes both measured (observed) attributes and latent traits.
D. includes both correlated and uncorrelated attributes.
LISREL, a structural equation (causal) modeling technique, is used to test causal hypotheses about relationships among measured variables and the latent traits those variables are believed to measure.
a. Incorrect See explanation for response c.
b. Incorrect See explanation for response c.
c. CORRECT In contrast to path analysis models, which predict the causal relationships among measured attributes only, LISREL models incorporate both measured attributes and latent traits. Additional information about LISREL and path analysis is provided in the Statistics and Research Design chapter of the written study materials.
d. Incorrect See explanation for response c.
The correct answer is: includes both measured (observed) attributes and latent traits.
To statistically analyze rank-ordered data obtained from two correlated groups, you would use which of the following?
Select one:
A. Mann-Whitney U
B. Kruskal-Wallis
C. Wilcoxon
D. ANCOVA
For the exam, you want to be familiar with the appropriate use of all of the tests listed in the answers to this question. Additional information on these tests is provided in the Statistics and Research Design chapter of the written study materials.
a. Incorrect The Mann-Whitney U test is used to analyze rank-ordered data from two independent groups.
b. Incorrect The Kruskal-Wallis test is used to analyze rank-ordered data from two or more independent groups.
c. CORRECT Knowing that the full name of this test is the Wilcoxon matched-pairs signed-ranks test would have helped you identify it as the correct response. The Wilcoxon is the appropriate test for rank-ordered data that have been obtained from correlated groups (e.g., groups that have been formed by matching participants on the basis of their scores on a pretest or extraneous variable and then randomly assigning members of each matched pair to one of two groups).
d. Incorrect The ANCOVA is a type of analysis of variance that allows the researcher to statistically remove the effects of an extraneous variable. Like other forms of the analysis of variance, it is used when data represent an interval or ratio scale of measurement.
The correct answer is: Wilcoxon
When using stepwise multiple regression the addition of predictors to the equation is usually based on:
Select one:
A. a predefined model or theory.
B. the magnitude of R-squared.
C. the proportion of accurate versus inaccurate decisions made.
D. the magnitude of the eigenvalues
The types of multiple regression include simple, hierarchical, and stepwise. As its name implies, stepwise regression involves adding (or subtracting) predictors to the multiple regression equation one at a time.
a. Incorrect This describes hierarchical multiple regression.
b. CORRECT When using stepwise multiple regression, each predictor is retained in the equation as long as it contributes significantly to the total amount of variability in the criterion that is explained by the combined predictors. The proportion of explained variability is measured by R-squared.
c. Incorrect This sounds like the basis for determining if predictors have incremental validity, which may be a consideration in multiple regression. However, this is not the best answer to this question.
d. Incorrect This refers to factor analysis.
The correct answer is: the magnitude of R-squared.
A factorial design:
Select one:
A. always includes two or more dependent variables.
B. always includes two or more independent variables.
C. is used to control order effects.
D. is used to evaluate the effects of pretesting.
The term “factor” in factorial design refers to independent variables.
a. Incorrect See explanation for response b.
b. CORRECT A factorial research design is any design that includes two or more “factors” (independent variables).
c. Incorrect See explanation for response b.
d. Incorrect See explanation for response b.
The correct answer is: always includes two or more independent variables.
On the basis of the results of the t-test a psychologist uses to analyze the data she collects, the psychologist concludes that her results are “significant at the .01 level.” This means that:
Select one:
A. there is a 1% chance that she will incorrectly reject the null hypothesis.
B. there is a 1% chance that she will incorrectly retain the null hypothesis.
C. there is a 99% chance that she will incorrectly reject the null hypothesis.
D. there is a 99% chance that she will incorrectly retain the null hypothesis.
The level of significance (alpha) determines the location of the boundary between the regions of likely and unlikely values in the sampling distribution. When results are significant at the chosen level of significance, this means that the results are in the region of unlikely values and that the null hypothesis should be rejected.
a. CORRECT Significance at the .01 level means that there is a 1% chance that the obtained value (e.g., the mean or the difference between means) could have occurred by chance alone given the value specified in the null hypothesis. In other words, there is a 1% probability that the null hypothesis will be incorrectly rejected (that a Type I error will be made).
b. Incorrect The probability of incorrectly retaining the null hypothesis (i.e., of retaining a false null hypothesis) is equal to beta, not alpha.
c. Incorrect See explanation for response a.
d. Incorrect Because the results are statistically significant, the psychologist will reject (not retain) the null hypothesis.
The correct answer is: there is a 1% chance that she will incorrectly reject the null hypothesis.
To analyze the relationship between gender and Holland’s six occupational themes, the appropriate statistical test would be which of the following?
Select one:
A. single-sample chi-square
B. multiple-sample chi-square
C. one-way ANOVA
D. factorial ANOVA
The study described in this question has one independent variable (gender) and one dependent variable (Holland’s six occupational themes), and the dependent variable is measured on a nominal scale.
a. Incorrect The single-sample chi-square test is appropriate for descriptive studies that include a single nominal variable.
b. CORRECT The multiple-sample chi-square test is appropriate for studies that include two or more variables and the data to be analyzed represent a nominal scale.
c. Incorrect The one-way ANOVA is appropriate for studies assessing the impact of a single independent variable on a single dependent variable that is measured on an interval or ratio scale.
d. Incorrect The factorial ANOVA is appropriate for studies assessing the impact of two or more independent variables on a single dependent variable that is measured on an interval or ratio scale.
The correct answer is: multiple-sample chi-square
Which of the following is the appropriate multivariate technique when using two or more continous predictors to predict status on two or more continuous criteria?
Select one:
A. logistic regression
B. linear regression
C. discriminant function analysis
D. canonical correlation
For the exam, you want to be familiar with all four techniques listed in the answers to this question, which are described in the Statistics and Research Design chapter of the written study materials.
a. Incorrect See explanation for response d.
b. Incorrect See explanation for response d.
c. Incorrect See explanation for response d.
d. CORRECT Of the techniques listed in the answers, canonical correlation is the only one that is appropriate when two or more continuous (interval or ratio) predictors will be used to predict status on two or more continuous criteria.
The correct answer is: canonical correlation
When reviewing the data from her study’s two treatment groups, a researcher discovers that the standard deviations of the two groups differ. If the researcher is planning to use the t-test for independent samples to analyze her data, this is:
Select one:
A. not a problem.
B. not likely to be a problem as long as the two groups have the same number of participants.
C. not likely to be a problem as long as the two distributions have a rectangular shape.
D. not likely to be a problem as long as the data represent an interval or ratio scale of measurement.
The parametric tests are fairly “robust” with regard to a violation of the assumptions that should be met in order to use them, and their robustness is increased under certain conditions.
b. CORRECT When groups are equal in size, a violation of the assumption of homogeneity of variances will probably not substantially affect the results of the t-test.
c. Incorrect One of the assumptions of the t-test is that the distribution of scores is normally shaped.
d. Incorrect Use of the t-test requires that the data represent an interval or ratio scale.
The correct answer is: not likely to be a problem as long as the two groups have the same number of participants.
