Experimental Basics
What is the purpose of experimental research?
To determine cause-and-effect relationships
What is the most common way to control for extraneous variables?
Randomization.
What is internal validity?
The extent to which a study accurately establishes a cause-effect relationship.
What is the difference between an independent and dependent variable?
IV is manipulated; DV is measured.
What is the difference between a control group and an experimental group?
The experimental group gets the treatment; the control does not
How does history threaten validity?
An external event affects participants during the study
What is a hypothesis?
A testable statement predicting the relationship between variables.
What does a pretest-posttest design involve?
Testing participants before and after treatment.
What is maturation, and how does it threaten validity?
Natural changes in participants over time that affect results.
What makes a study a true experiment?
Random assignment to groups
What is the Solomon four-group design used for?
To control for pretest-treatment interaction.
What is the Hawthorne effect?
Participants change their behavior because they know they’re being observed.
Name one major advantage of experimental research over correlational research.
It allows for causal conclusions.
What is counterbalancing?
A method to control for order effects in repeated measures
What is statistical regression, and why is it a concern?
Extreme scores tend to move closer to the average on retesting.