AP Psych Vocab Quiz

random sample

A group chosen from a population where every person has an equal chance of being selected.

random selection

The process of choosing people from a population in a way that gives everyone an equal chance.

random assignment

Putting participants into different groups (like experimental or control) by chance, not choice.

representative sample

A sample that reflects the important characteristics of the larger population.

population

The entire group of people or things a researcher is interested in studying.

reliability

The consistency of results when something is measured repeatedly.

validity

How well a test or study measures what it is supposed to measure.

independent variable

The factor that the researcher changes or manipulates.

dependent variable

The outcome or result that is measured in an experiment.

confounding variable

An outside factor that could affect the results and confuse interpretation.

experimental group

The group that receives the treatment or condition being tested.

control group

The group that does not get the treatment, used for comparison.

placebo group

A control group that gets a "fake" treatment (like a sugar pill) to test the real treatment's effect.

single blind design

An experiment where participants don't know if they're in the experimental or control group, but researchers do.

double blind design

An experiment where neither participants nor researchers know who is in which group.

placebo effect

When people show improvement just because they believe they are receiving a real treatment.