1. Factorial experiments

2. Types of independent variables
Participant (measured)
Straightforward manipulations
Staged manipulations

3. Factorial designs More than one IV
All possible combinations in the study
Why have more than 1 IV?

4. Null results IV may not be important Maybe didn’t manipulate correctly
Confounds
Unreliable DV
Restricted range (floor and ceiling effects)
Didn’t have enough power

5. Types of DVs Self-report Behavioral Physiological
Why have more than 1 DV?

6. Threats to internal validity
History
Maturation
Testing
Instrumentation
Regression to the mean
Selection
Mortality

7. Test yourself
A researcher asks liberals and conservatives to read an article that has the header of either FoxNews or NBC (the article actually came from the AP). Participants then indicate how biased they think the article is against the liberal vs. conservative viewpoint (single scale).
IV? DV? Confound? Type of design? How many people to have 10 per?
What if he found that liberals perceived the article as more biased, regardless of header?
What if he found that liberals perceived the article as more biased when they thought it came from Fox, and conservatives when they thought it came from NBC?