Interactions
The IVs in a factorial design are also called
factors
Unique conditions in a factorial design
Cells
Participants are not randomly assigned to groups and are tested only once, after exposure to either one level of the independent variable or the other.
nonequivalent control group posttest-only design
Extraneous variables that may influence the results of our study
Design confounds
Serves the same purpose as an independent variable, but researchers do not have full experimental control over it.
Quasi-independent variable
An _______ effect occurs when the effect of one IV depends on the level of another IV.
interaction
a variable whose levels are selected (measured) not manipulated.
(Social Identities)
Participant variable
Measuring a variable repeatedly, before, during, and after the “interruption” from some event
interrupted time-series design
In designs with pretests and posttests, ______ occurs when people drop out of a study over time.
Attrition threat
In conducting quasi-experimental designs, researchers tend to give up some ________ in exchange for ________.
Internal Validity; External Validity
An experiment in which there are two or more IVs
Factorial design
The means for each level of an IV, averaging over levels of the other IV.
Marginal Means
A researcher observes a behavior for an extended “baseline” period before the intervention or treatment is introduced.
Stable-baseline designs
When an external, historical event happens for everyone in a study at the same time as the treatment. it is unclear whether the outcome is caused by the treatment or by the external event or factor.
History Threat
If quasi-experimental studies can be vulnerable to internal validity threats, why would a researcher use one?
Ethics; Real-world opportunities
Is there a difference in differences?
Two-way interactions
Researchers use marginal means to look for _____________
main effects
Researchers stagger their interventions across situations, times, or contexts.
Multiple-baseline designs
In a design with a pretest and posttest, an observed change could have emerged more or less spontaneously over time.
Maturation threat
What is the difference between a correlation and a quasi-experiment?
Quasi-experiments do a little more meddling
Are the differences in differences different?
Three-way interactions
This is the overall effect of one IV on the DV, averaging over levels of the other IV, and it identifies a simple difference.
Main effect
Researchers observe a baseline of behavior before treatment, next observe the behavior during treatment, and then remove the treatment to see whether the behavior reverts back.
Reversal designs
When an extreme finding is caused by a combination of random factors that are unlikely to happen in the same combination again, so the extreme finding becomes less extreme over time
Regression to the mean
What is the difference between a quasi-independent variable and a participant variable?
Participant variables are associated with social identities. Quasi-independent variables focus more on interventions.