Select Questions

Chapter 8

1. In a factorial design, subjects are assigned completely at random to one of the treatments; the design is a __________.

completely randomized design

Latin square design

randomized blocks design

within-subjects design

2. 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, three

four, three

one, four

3. 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.

randomized blocks

factorial

Latin square

completely randomized

4. 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 _________.

an interaction between diagnostic category and "feeling blue"

a limited main effect of exercise

an interaction between treatment (exercise) and diagnostic category

a main effect of diagnostic category

5. A(n) __________ occurs when the effect of one variable, X, on another variable, Y, depends upon a third variable, Z.

main effect of Z

main effect of X and an interaction between X and Y

interaction

main effect of X

6. A researcher investigates the influence of illumination levels (high, moderate, low) on reading speed, for texts varying in difficulty (complex, simple). In this factorial design, there are a total of __________ treatments.

7. In a __________ design, each subject receives all the treatments; in a _________ design, each subject receives only one treatment.

nonfactorial; factorial

within-subjects; between-subjects

between-subjects; within-subjects

factorial; nonfactorial

8. 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)

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

none of the F tests were statistically significant.

9. The evidence for interactions can be seen most clearly in which of the following?

a bar chart

a line chart

a scatterplot

a table of group means

10. In a within-subjects design ___________.

each subject receives only one treatment

there are two factors and at least one dependent variable

each subject receives all treatments

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

11. In Hall and Kataria's study evaluating different treatments for attention deficit hyperactive disorder, the children were tested on a delayed response task both when they were taking Ritalin and when they were not. A variable such as this involving repeated testing of the same subjects is called:

a within-subjects factor.

a subject factor.

a between-subjects factor.

an interaction.

12. Most people thrive on a diet containing phenylalanine; only the rare people with phenylketonuria suffer brain damage because of it. This is an example of a(n):

interaction.

main effect.

regression.

confounded effect.