Research Methods: Chapters 12 Flashcards
What is an interaction effect (interaction)?
Occurs when the impact of one independent variable on a dependent variable is different depending on the level of another independent variable.
Explain what a factorial design is.
A type of design in which there are two or more independent variables. Oftentimes, researchers cross the two independent variables, they study each possible combination of the independent variables.
What is a participant variable?
A variable whose levels are selected (measured), not manipulated. Because the levels are not manipulated, variables such as age or gender are not truly “independent” variables.
What is a main effect?
The overall effect of one independent variable on the dependent variable, averaging over the levels of the independent variable. In other words, a main effect is a simple difference. In a factorial design with two independent variables, there are two main effects.
Explain marginal means.
The arithmetic means for each level of an independent variable, averaging over levels of the other independent variable.
What are independent-groups, within-groups, and mixed factorial designs?
- Independent-groups factorial designs - Both independent variables are studied as independent-groups.
- Within-groups factorial designs - Both independent variables are manipulated as within-groups.
- Mixed factorial designs - One independent variable is manipulated as independent-groups and the other is manipulated as within-groups.
What is a quasi-experimental design?
A mixture of both experimental and non-experimental designs. There are variables being manipulated, but you can’t make a causal claim.
What is a quasi-experimental variable (subject variable)?
Variables that cannot be manipulated, randomly assigned, or controlled.
Ex. time, age, gender, IQ, or pregnancy status.
