Ch12

Question 1

interaction effects

Answer 1

Interaction effects (interaction): the effect of an independent variable depends on the level of another

Question 2

type of interactions

Answer 2

• crossover

-spreading

Question 3

Crossover interaction

Answer 3

Crossover interaction: “it depends”- (ex: ice cream cold, pancakes hot) looks like x on graph

Question 4

spreading interaction

Answer 4

Spreading: “only when”- (ex: dog sits when told, only when there’s a treat) looks like <

Question 5

Factorial design

Answer 5

Factorial design: studies two or more IVs (factors)

Question 6

Cells

Answer 6

unique conditions representing combinations of IV’s

Question 7

participant variable

Answer 7

Participant variable: in factorial design- a variable that’s levels are selected (measured but not manipulated) but act in place of a second IV (ex: age can’t be manipulated)

Question 8

moderators

Answer 8

Moderators (in factorial design): IV that changes relationship between another IV and the DV (results in an interaction)

Question 9

moderators

Answer 9

Moderators (in factorial design): IV that changes relationship between another IV and the DV (results in an interaction)

Question 10

main effect

Answer 10

Main effect: the effect of one independent variable on the DV, if you avg over/ignoring the levels of the other IV

Question 11

marginal means

Answer 11

Marginal means: means for each level of an IV if you avg over levels of the other IV

Question 12

computing interactions

Answer 12

• Start with one level of IV1, compute the difference btwn the levels of IV2 (using subtraction), then compute difference btwn levels of IV2 for the other level of IV1
• Then compare the numbers for each difference. If they are different enough it is statistically significant, there is an interaction

Question 13

Independent-groups factorial designs (between-subjects…)

Answer 13

both IV’s are studied as independent groups, so each cell has it’s own group of people

Question 14

Within-groups factorial designs (repeated measures…):

Answer 14

Within-groups factorial designs (repeated measures…): all participants are part of all of the conditions/cells

Question 15

mixed factorial design:

Answer 15

Mixed factorial design: one IV is manipulated as independent groups and the other is within-groups
(Intermediate # of participants)

Question 16

factorial design notation

Answer 16

the number tells how many levels of an IV, and the # of #’s tell how many IV’s

Question 17

2 x 2 x 2 factorial or three-way design

Answer 17

• two levels of each IV, 3 IVs
• 8 cells ((2x2)x2)
• 3 main effects to test, 3 two way interactions (avg over third v), 1 three way interaction

Question 18

how to depict three-way factorial design

Answer 18

Depict by constructing table twice, once for each level of the third IV, two side by side graphs

Question 19

what does it mean if a three way interaction is significant

Answer 19

• means the two-way interaction between two of the IVs depends on the level of the third IV

Question 20

how to tell if 3-way interaction

Answer 20

How to know if there is a three way interaction:
- If there is a two-way interaction for one level of the third v but not the other, OR

• If there are two different patterns of two-way interactions for the levels of the third v

Question 21

where to look in journal articles to see if design is factorial

Answer 21

Method section: find info about study design and variables
- _ x_ indicates factorial design, along with numbers of IVs and levels
- Also can see if within-groups or independent-groups, mixed factorial design

Results section: shows whether main effects and interactions are significant
- Significance, p value ( p < 0.05) or *
- MANOVA or ANOVA or F indicate factorial interactions

Question 22

in media, look to see if factorial

Answer 22

• look for “It depends” or “only when”
• Look for participant variables (age, gender, ethnicity, etc.)
  It might moderate another variable, and when there’s a moderator then there’s an interaction, a factorial design