Psy 136 Chapter 12

A researcher performs a 3 xx 4 ANOVA with 5 participants in each cell of the study design. What is the within-groups degrees of freedom?

48

A researcher performs a 3 xx 4 ANOVA with 5 participants in each cell of the study design. What is the degrees of freedom for the interaction?

6

In a two-way between-groups ANOVA, SSrows = 4.5, SScolumns = 7.25, SSinteraction = 0.56, SSwithin = 8.89, and SStotal = 21.2. What is the R2 value for the main effect represented in the columns?

.45

In a two-way between-groups ANOVA, MSrows = 2.7, MScolumns = 10.5, MSinteraction = 13.2, and MSwithin = 2.5. What is the F value associated with the rows?

1.08

A researcher is interested in whether caffeine influences participants' performance on different kinds of memory tests. The researcher randomly assigns participants to one of two conditions: caffeinated drink or a placebo (non-caffeinated) drink. The researcher also randomly assigns participants to receive either an implicit memory test or an explicit memory test. The researcher then tests everyone at 8 A.M., one hour after drinking their assigned beverage. How would you label the ANOVA used to analyze these data?

2 x2 between-groups ANOVA

Roediger and Karpicke (2006) investigated whether the test-enhanced learning effect (the demonstration that repeated testing improves memory for material) was due merely to repeated exposure to material. They randomly assigned participants to one of two study conditions (study-study or study-test) and to one of three retention interval conditions (final test at a delay of 5 minutes, 2 days, or 1 week). The dependent variable was the proportion of idea units recalled from an encyclopedia passage. How would you label the analysis for these data?

2 x3 between-groups ANOVA

The owners of the Syfy channel are interested in whether watching the Syfy channel causes people to become "geeky," and if so, whether any such effects depend on a person's gender. They hire you to design and carry out the appropriate study. You design a study in which you randomly assign an equal number of men and women to watch either 0, 3, 5, or 9 hours of the Syfy channel each week for 6 weeks. How would you label the ANOVA used to analyze your data?

4 x 2 between-groups ANOVA

A researcher performs a 3 xx 4 ANOVA with 5 participants in each cell of the study design. What is the within-groups degrees of freedom?

4.2

Roediger and Karpicke (2006) investigated whether the test-enhanced learning effect (the demonstration that repeated testing improves memory for material) was due merely to repeated exposure to material. They randomly assigned participants to one of two study conditions (study-study or study-test) and to one of three retention interval conditions (final test at a delay of 5 minutes, 2 days, or 1 week). The dependent variable was the proportion of idea units recalled from an encyclopedia passage. How many cells does this study have?

6

A researcher is interested in the effects of playing violent video games on aggressive behavior. There are two independent variables in his study: 1) the type of video game played (violent or non-violent) and 2) the amount of time spent playing the video game (either one day or one week). At the end of the testing phase, participants are given a test to measure their aggressive response in an ambiguous situation. If a significant main effect is found, should we conduct a post hoc test? Why?

No; we should not conduct post hoc test because each main effect has only two groups.

In a 3 × 3 between-groups ANOVA with 5 participants per cell, MSrows = 2.7, MScolumns =0.5, MSinteraction = 13.2, and MSwithin = 2.5. What decision should the research make regarding the main effect represented in the rows?

The null hypothesis should not be rejected.

In a factorial ANOVA, a cell reflects:

a unique combination of levels of the independent variables

Main effects refer to the:

effect of a single independent variable on the dependent variable, disregarding any other independent variables in the study.

A "factor" in a factorial ANOVA refers to a(n) _____.

independent variable

The degrees of freedom for the interaction in a two-way ANOVA is calculated by:

multiplying together the degrees of freedom associated with each of your main effects.

The within-groups degrees of freedom in a two-way ANOVA is calculated by:

subtracting a single participant from each cell of the study and then adding the results for all of the cells.

An interaction occurs when

the effects of one of your independent variables depends on the level of the other independent variable.

An interaction occurs when:

the effects of one of your independent variables depends on the level of the other independent variable.

In a table, depicting the cells of a two-way ANOVA, the marginal means reflect:

the two main effects.

In a two-way factorial ANOVA, we obtain separate F values for

two main effects and a single interaction.

In a two-way factorial ANOVA, we obtain separate F values for:

two main effects and a single interaction.

A hypothesis test with two nominal independent variables and a scale dependent variable is a _____.

two-way ANOVA