Variables
The variable that the experimenter manipulates.
Independent Variable
An attempt to evenly distribute participant differences across experimental conditions in an independent group design.
What is random assignment?
In this factorial design, both IVs have 2 levels.
What is a 2x2 (crossed factorial) design?
This is the average score of all groups at one level of one variable.
What is the marginal mean?
A variable that is kept constant to prevent its influence.
Control variable
Along with covariance & temporal precedence, this is a criterion of causality.
What is internal validity.
A group that doesn't receive the treatment and shows how people behave when they are not exposed to the experimental treatment.
What is a control group?
This type of effect occurs when one independent variable influences the dependent variable, regardless of the other variable.
What is a main effect?
The difference between scores of two levels of food type keeping the temperature constant.
What is the simple main effect?
Here are 2 examples of it. Aggression can be measured as a physical action, e.g., kicking or hitting. Another way is to record the intensity of shocks given by one to another.
What is operational definition?
When Participants know they are being tested and change behaviors (intentions are often kept secret).
What are demand characteristics?
When the same group of participants experiences multiple conditions
What is a within-groups design (within-subjects)?
Here's an example! A researcher finds that the effect of caffeine on memory depends on the amount of sleep a participant got.
What is an interaction effect?
Subtract the simple main effects of one IV at different levels of another IV.
What is the interaction effect?
Add this to go from a 2x2 design to a 2x2x3 design.
What is another independent variable?
You examine this validity when you wonder how big is the effect of one variable on another.
What is statistical validity?
A way of trying to control for order effects in a repeated measures design, e.g. half the participants do condition A followed by B and the other half do B followed by A
What is counterbalancing?
This is the term for a factorial design that includes at least one between-subjects factor and one within-subjects factor.
What's a mixed-factorial design?
In a 2x2 design, _ is the number of main effects.
What is 4?
This is a term for a variable that changes the effect of an IV on the DV.
What is a moderating variable/moderator?
It helps to check whether the manipulation of the IV was successful.
What is a manipulation check?
Participants are matched on some variable that is important to the experiment and then one of each pair is allocated to a different condition.
What is a matched groups design?
Here's a great example! The effect of caffeine on memory depends on sleep among women but not men.
What's a 3-way interaction?
In a 2x2x2 design, this is the number of 2-way interactions we can calculate.
What is 3?