Chp 10: Complex Experimental Designs (PSY302) Flashcards
In the simplest experimental design, there are only _____ levels of the IV
2
__________levels can provide more info abt the relationship.
3 or more
If the curvilinear relationship is predicted, at least _____ levels must be used.
3
Researchers are also frequently interested in comparing _______ than 2 groups.
more
Def: factorial designs
Factorial designs: experimental designs with more than a single IV/factor
Factorial designs yield 2 kinds of info:
Main effect
An interaction
Def: main effect
Main effect: the direct effect of an IV on a DV
The effect of each variable by itself
Each DV is the overall relationship between that IV and the DV.
The simplest factorial design is a _________ factorial design, that has 2 IV, each having 2 levels:
This results in ___ experimental condition
2 by 2, 4
Interaction: between 2 IVs, the effect on one IV depends on the __________ level of the other.
Interactions _______ be obtained in a simple experimental design in which only a single IV is manipulated
participation, cannot
If an interaction exists, the main effects of the IV must be ________.
qualified
Interactions can be seen easily when the means for all conditions are presented in a ________.
graph
When analyzing the results form a 2 by 2 factorial design, researchers deal with several possibilities:
There may or might not be a significant main effect for IV A
There may or may not be a significant effect for IV B
There may or may not be a significant interaction between any of the IVs
Def: analysis of variance
Analysis of variance: used to assess the statistical significance of main effects & interactions in a factorial design.
Simple main effect analysis examines ___________ at each level of the IV.
mean diffs
The 3 methods for assigning participants to conditions affect how many are necessary for an experiment:
The independent groups (between subjects) design
Repeated measures (within subjects) design
A mixed factorial design
