R squared is the:
a. coefficient of multiple determination
b. coefficient of stability
c. coefficient of internal consistency
d. silver character on
... [Show More] "Star Wars" - correct answer a. coefficient of multiple determination
When data points are widely scattered around a regression line, this indicates:
a. low homoscedasticity
b. low correlation coefficient
c. low heteroscedasticity
d. high heteroscedasticity - correct answer b. low correlation coefficient
Heteroscedasticity - correct answer The scatter is uneven (unequal) at different points on the regression line. For example, there might be high variability around the regression line at low X (predictor) values and low variability around the line at high X values. It is different amounts of scatter, but not high scatter
A psychologist in a hospital is conducting research designed to assess the effects of a new drug on the social behavior of psychotic patients. Which of the following would be the best way to decrease experimenter bias in this type of study?
a. randomized block design
b. a Solomon four-group design
c. counterbalancing
d. a double-blind study - correct answer d. a double blind study
Which of the following is a measure of "amount of variability accounted for"?
a. Cohen's d
b. F-ratio
c. alpha
d. eta squared - correct answer d. eta squared
Alpha - correct answer Level of significance set by a researcher prior to analyzing data
Cohen's d - correct answer Used as an index of effect size, but it is a measure of the mean difference between two groups.
F-ratio - correct answer Statistic calculated when using the analysis of variance
The eta coefficient would be used to
a. estimate the strength of a nonlinear relationship between two continuous variables
b. estimate the strength of the relationship between two rank-ordered variables
c. estimate the strength of the relationship between two dichotomous variables
d. estimate the strength of the relationship between a dichotomous variable and a continuous variable - correct answer a. estimate the strength of a nonlinear relationship between two continuous variables.
The most common correlation coefficient - correct answer Pearson r
Pearson r - correct answer Used to measure the relationship between two continuous variables that are related in a linear way
Note: eta is used when there is a nonlinear relationship
Phi Coefficient - correct answer Can be used to measure the correlation between two dichotomous variables (i.e, variables that can take one of two values)
Point-Bisceral Correlation - correct answer Used to measure the correlation between a dichotomous variable and a continuous variable.
Spearmena's rho - correct answer Used to measure the correlation between two sets of ranked data
You have conducted a study to assess the relationship between salary and job performance, and you find a significant correlation between these two variables. You assistant tells you that the data fail to take into account a $25.00 cost of living raise that every empoyee received. You should:
a. assume the correlation will not be affected
b. not be concerned since the added amount is too small to make a significant difference
c. decide that the raise invalidated the research
d. reanalyze the data after the raises have been added to the current salaries. - correct answer a. assume the correlation will not be affected
Note that you are adding a constant to each score in one of both data sets does not change the relationship
A psychological researcher would like to determine what variables best distinguish between patients who benefit from psychotherapy and patients who do not. To identify these variables, the research would most likely use which of the following?
a. canonical correlation
b. factor analysis
c. MANOVA
d. discriminant function analysis - correct answer d.
Factor Analysis - correct answer Used to reduce variability in a set of variables to a smaller set of unobserved variables, or factors. For example, factor analysis might be used to confirm a theory that score differences on a variety of intelligence measures can be explained in terms of two factors, verbal intelligence and performance intelligence.
Discriminant function analysis - correct answer Used to identify variables that distinguish between two or more existing or naturally occurring groups. It would involve collecting data on a variety fo measures and determining which combination of them best predict differences between groups. [Show Less]