Psych 2185 exam 4

How do we calculate a marginal mean?

Add the two scores up and then divide by 2

What is a marginal mean?

Average mean of scores for each i.v.

What are the key elements in an experimental design?

Independent variable, dependent variable, conditions of the independent variable

ANOVA

Inferential test used for designs with three or more sample Means

What is the difference between Main Effects and Interactions?

Main Effects: tests the difference b/w ALL means for EACH level of an i.v. In an ANOVA Interactions: tests the effect of ONE i.v. at EACH level of an i.v. in an ANOVA

What is an Experiment Design?

Manipulations if an independent variable that helps contain extraneous/unwanted variables that could affect the results

Simple Effects test

Stat tests conducted to characterize an interaction effect when one is found in an ANOVA

Main Effect

Test of the differences b/w ALL means for each level of an i.v. in an ANOVA

Interaction Effect

Tests the effect of one i.v. at each level of another i.v. in an ANOVA

What is a factorial design?

The experiment contains more than one i.v.

What is the advantage of using a factorial design?

We can be more efficient in testing the effects of multiple i.v.'s AND examine the combined effects of the i.v.'s on the d.v.'s

What would happen if we didn't include multiple i.v.'s?

We would not detect the different effects a factor has on a behavior in different situations