Lecture 10: Complex experimental design

Question 1

What is a factorial research design? What does IV mean?

3pts

Answer 1

• Have 2 or more IV’s, each of which has 2 or more levels/conditions
• IV= “factor”
• 3x 2 factorial design–> # levels IV 1 by # levels IV 2

Question 2

In factorial research designs, researchers examine: What is a main effect?

Answer 2

The effect of each individual IV on the DV (if the marginal means are different, there is a main effect)

Question 3

In factorial research designs, researchers examine: What is an interaction effect? Give an example.

Answer 3

The combined effect of the two IVs on the DV
- E.g., does the effect of one IV differ depending on the level/condition of the other IV

Question 4

What are the three types of factorial research designs?

3pts

Answer 4

• Fully between-subjects (all between-subjects IVs)
• Fully within-subjects (all within-subjects IVs)
• Mixed factorial design (at least 2 between-subjects IV, at least 1 within-subjects IV)

Question 5

Experimental designs become increasingly complex when researchers:

2pts

Answer 5

• Consider an IV with more than 2 levels/conditions; and/or
• Consider more than 1 IV (factorial designs)