Select Questions

Chapter 8

1. A(n) ______ occurs when the effect of one variable, A, on another variable, X, depends on a third variable, B.

interaction

main effect

regression

anomaly

2. When factors such as age and sex, which are based upon characteristics of subjects, are used as a factor in a factorial design, __________.

study results are easy to interpret

subjects may be assigned in a completely random fashion

it may be because it is not feasible or ethical to manipulate that factor (e.g., stress).

results will probably not generalize

3. A researcher investigates the effect of caffeine on problem solving speed. She administers either a placebo, 1, 2, or 5 mg of caffeine to subjects and measures the average time it takes them to solve three problems. This design contains _______________ factor(s) with __________ level(s).

four, one

one, four

four, three

one, three

4. An experiment with two independent variables, each of which has two levels, in which all combinations of treatments are included, is called a(n) ________ design.

interaction

two-way factorial

multiple factor

2x2 factorial

5. In the analysis of the two-factor design shown in the summary table below, which F test(s) was/were statistically significant?
Table
Analysis of Variance
Summary Table for Depression Scores
Source              df       F
A = Drug Th         1      1.86
B = Cog Beh Th     1     12.23*
A x B                  1       2.03
Error                30
* p < .05

the F test showing the interaction effect, A x B

the F test showing the main effect of A (Drug Treatment)

none of the F tests were statistically significant.

the F test showing the main effect of B (Cognitive Behavior Therapy)

6. The design that allows the researcher to test for interactions between variables is the __________.

within-subjects design

Latin square design

factorial design

between-subjects design

7. A __________ design is a design with two or more independent variables, in which the complete set of treatments is defined by the product of the levels of the independent variables.

factorial

Latin square

randomized blocks

completely randomized

8. See the summary table below. In the analysis of this two-factor design, __________ F test(s) was/were computed.
Table
Analysis of Variance
Summary Table for Depression Scores
Source              df       F
A = Drug Th         1      1.86
B = Cog Beh Th     1     12.23*
A x B                  1       2.03
Error                30
* p < .05

9. Researchers have investigated the effect of exercise on depression. They have found that exercise decreases "feeling blue" in unipolar depressives but has no effect upon those suffering from seasonal affective disorder. The finding, that the effects of exercise depends upon diagnostic category, is an example of _________.

a limited main effect of exercise

a main effect of diagnostic category

an interaction between diagnostic category and "feeling blue"

an interaction between treatment (exercise) and diagnostic category

10. In a within-subjects design ___________.

each subject receives only one treatment

there are two factors and at least one dependent variable

there are at least two factors and at least one dependent variable

each subject receives all treatments

11. The design that best controls for individual differences between subjects, using the fewest number of subjects, is the __________.

randomized block design

completely randomized design

between-subjects design

within-subjects design

12. In a factorial design, the total number of treatments __________.

equals the product of the number of levels of each of the independent variables

equals the sum of the number of independent variables and the number of dependent variables

equals the number of levels of the first independent variable plus the number of dependent variables

equals the number of independent variables