All GRE Subject Test: Psychology Resources
Example Questions
Example Question #51 : Other Areas
Which statistical procedure is best used when there are two or more independent variables, the variables can be held fixed with respect to each other, and a conditional expectation of dependent variable given the independent variables is required?
Spearman's rank-correlation coefficient
All of these
Analysis of covariance (ANCOVA)
Regression analysis
Two-way ANOVA
Regression analysis
A regression analysis, so long as all but one independent variable at a time can be held fixed, is able to produce a predictive window called a conditional expectation that allows for prediction of dependent variable values given set independent variable levels.
Example Question #52 : Other Areas
The primary difference between a sequential sum of squares and an adjusted sum of squares is that the adjusted sum of squares __________.
only works for models with large values for n
None of these
depends on the order in which factors are entered into the model
does not depend on the order in which factors are entered into the model
only works for models with small values for n
does not depend on the order in which factors are entered into the model
An adjusted sum of squares is a model that determines the amount of remaining variance in a model is explained by a factor given that all the other factors are already in the model. For a sequential sum of squares, the amount of variance in a model is explained only given the factors which are already in the model. Thus, the first factor inserted in a sequential sum of squares carries the most weight.
Example Question #53 : Other Areas
All of the following are true about the General Linear Model (GLM) except which of the following?
It works irrespective of the error terms in each matrix
It can test hypotheses using either multivariate or multiple independent univariate tests
It generalizes multiple linear regression to more than one dependent variable
It incorporates F-testing, t-testing, linear regression, and ANOVA models
All of these
It works irrespective of the error terms in each matrix
The general linear model, expressed as , works by comparing a model matrix (sometimes called a design matrix) to a parametric estimate, while also factoring for generalized error terms within the data. It works best when errors are uncorrelated across measurements.
Example Question #54 : Other Areas
One appropriate use of a biased ANOVA term for expected mean squares might be which of the following?
If the population means are not equal to one another (the null hypothesis is false)
If the factors are expected to have an interaction
If one or more terms are nonparametric in the model
None of these
If the population mean cannot be estimated
If the population means are not equal to one another (the null hypothesis is false)
A biased EMS is most commonly used when random terms are part of the factors in the model (and thus, when the population means cannot be reasonably assumed to be equal irrespective of treatment effect).
Example Question #55 : Other Areas
All of the following are true about Pearson's r except which of the following?
Sampling distribution can be made to fit Student's t-distribution
All of these
Sample r is extremely accurate at estimating population correlation coefficients if sample size is large
Strength of correlation ranges from -1 to 1
Confidence intervals cannot be established for weak values of r
Confidence intervals cannot be established for weak values of r
Constructing a confidence interval for Pearson's r can be done through a process called "bootstrapping", which involves re-sampling with replacement a certain number of values in each correlation a large number of times.
Example Question #211 : Gre Subject Test: Psychology
Which of the following is a situation where you might prefer a one-tailed test to a two-tailed test?
When comparisons between groups are more important then comparisons across groups
When the sample size is excessively high
When the sample size is excessively low
When only deviations above a particular score are of research interest
None of these
When only deviations above a particular score are of research interest
A two-tailed test differs from a one-tailed test primarily in that it examines deviations both above and below a particular mean. Thus, a one-tailed test is most appropriate when only one direction of deviation is of relevant interest.
Example Question #212 : Gre Subject Test: Psychology
Each of the following is true about homoscedasticity except which of the following?
It follows the assumption that standard deviations of the error terms are constant within measures
It largely determines goodness of fit (as defined by Pearson's r)
It can be tested by regression of squared residuals
Meeting the assumption of homoscedasticity is necessary to demonstrate an unbiased estimate
None of these
Meeting the assumption of homoscedasticity is necessary to demonstrate an unbiased estimate
Homoscedasticity is explicitly not required to ensure unbiased, asymptotically normal, or reliable results. They are, however, required to show goodness of fit.
Example Question #213 : Gre Subject Test: Psychology
When testing for non-groupwise homogeneity of variance, the most sensitive test to departures from normality is generally which of the following?
None of these
Brown-Forsythe test
Levene's test
Goldfeld-Quandt test
Bartlett's test
Bartlett's test
Levene's test and the Brown-Forsythe test for homogeneity of variance are not very sensitive to departures from normality, which makes them more useful as tests for nonstandard data sets but less able to predict goodness of fit. Goldfeld-Quandt is a test for groupwise homogeneity of variance, and is useless for the stated purpose.
Example Question #214 : Gre Subject Test: Psychology
Dr. Crawford believes she has invented a pill to help with student memorization. For a trial experiment, she gathered two groups of twenty students. She gave the twenty students in Group A the “smart pill”, and the twenty students in Group B a sugar pill. After waiting five minutes, both groups of students were given a list of forty words, and were instructed to memorize the entire list in any order. The students were given five minutes to memorize the list. The students were then asked to verbally recite all of the words they could remember in any order within three minutes.
Group A recited an average of fifteen words, while Group B recited an average of ten words.
Which statistical analysis should Dr. Crawford use?
Cannonical correlation
T-test
Chi-square
ANOVA
Pearson-R
T-test
A t-test is most appropriate when only analyzing two variables. Dr. Crawford is analyzing the means between Group A, who received the smart pill, and Group B, who did not. This test will determine whether the differences in means is due to chance or if there is a statistically sound significant difference.
Example Question #51 : Measurement & Methodology
Dr. Crawford believes she has invented a pill to help with student memorization. For a trial experiment, she gathered two groups of twenty students. She gave the twenty students in Group A the “smart pill”, and the twenty students in Group B a sugar pill. After waiting five minutes, both groups of students were given a list of forty words, and were instructed to memorize the entire list in any order. The students were given five minutes to memorize the list. The students were then asked to verbally recite all of the words they could remember in any order within three minutes.
Group A recited an average of fifteen words, while Group B recited an average of ten words.
Dr. Crawford can for sure reject her null hypothesis if she obtains a calculated p-value equal to which of the following?
None of these
The p-value represents the probability that differences in means are due to random chance and not due to the independent variable’s effects. The smaller the p-value, the less likely it is that differences in means are random. This supports the researcher rejecting the null hypothesis; therefore, the following p-value is the correct answer: