Interaction Practice Questions

Interaction practice questions.

General question:

What is the name of the experimental design shown below?

What do we call the four central cells with numbers in them?

What do we call the cells at the right and the cells at the bottom with averages in them?

General comment: We use the terms “variable” and “factor” interchangeably.

Also, the use of 1 and 2 or A and B is arbitrary. (Compare the table labels in the first four tables below!)

HINT: if you ever want to know whether the means are the same for either variable 1 or for variable 2, ask yourself if the totals are the same. Since the means in these examples are always going to be the totals divided by 2, if the totals are the same, the means will be the same. You don’t have to actually calculate the means to know that the means are going to be the same!

Question 1: This study examined the effect of amount of pizza eaten (1 or 3 slices) and amount of TV watching afterwards (30 or 90 minutes) on sleepiness. Describe the four conditions.

Question 2: This study examined the effect of type of test (multiple choice or true false) and amount of time pressure (high or low) on test score. Describe the four conditions. Explain how you could make it a 2 x 3 design. How many conditions would there be then?

Question 3: This study examined the effect of amount of study time (1 or 2 hours) and quietness of study room (very quiet or very noisy) on amount of material retained the following day. Describe the four conditions. Explain how you could make it a 3 x 3 design. How many conditions would there be then?

Question 4: This study examined the effect of assertiveness (high vs low) and gender (male vs female) on perceived attractiveness. Describe the four conditions. Describe a way you could make it a 2 x 2 x 2 design. How many conditions would there be then?

Question 5: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of variable A?

Is there a main effect of variable B?

Is there an interaction?

Question 6: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of factor 1?

Is there a main effect of factor 2?

Is there an interaction?

Question 7: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of variable A?

Is there a main effect of variable B?

Is there an interaction?

Question 8: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of factor 1?

Is there a main effect of factor 2?

Is there an interaction?

Question 9: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of variable A?

Is there a main effect of variable B?

Is there an interaction?

Question 10: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of factor 1?

Is there a main effect of factor 2?

Is there an interaction?

Question 11: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of variable A?

Is there a main effect of variable B?

Is there an interaction?

Question 12: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of factor 1?

Is there a main effect of factor 2?

Is there an interaction?

Question 13: Suppose the data in this 2 x 2 design came out as follows:

Is there a main effect of variable A?

Is there a main effect of variable B?

Is there an interaction?

Question 14: Suppose the data in this 2 x 2 design came out as follows:

What would X need to be to produce no interaction?

What would X need to be to produce no main effect for variable 1?

What would X need to be to produce no main effect for variable 2?

TEST YOURSELF by asking the above three questions with lots of other sample numbers in the first three cells.

TEST YOURSELF SOME MORE by trying the same thing but leaving one of the other cells blank. For example, leave the top left cell empty but fill in the top right, bottom left, bottom right, and then try to come up with the number that would produce no interaction (for example). You could probably stay up all night trying different variations, and having just SO MUCH FUN that your roommate becomes envious and wants you to also teach her this game. When the game begins to bore you because you really understand it and are sure you are getting every single one correct, then it’s time to stop.

C:\Documents and Settings\vomsaaw\Application Data\Microsoft\Templates\Normal.dot, 11/22/20184:14 PM. Page 1 of 1