Section 2.3: Correlation and Experimentation - Terms

Correlation

A measure of the relationship between two variables, indicating how they change together but not proving causation.

Correlation coefficient

A statistical measure (ranging from -1 to +1) that indicates the strength and direction of the relationship between two variables.

Scatterplot

A graphical representation of data points that show the relationship between two variables.

Variable

Any characteristic, condition, or factor that can change or be manipulated in an experiment.

Causation

A direct cause-and-effect relationship where one variable produces a change in another.

Illusory correlation

The perception of a relationship between two variables when in reality it doesn't actually exists.

Regression toward the mean

The statistical tendency for extreme scores or unusual results to return closer to the average over time.

Experiment

A research method that manipulates variables to determine cause-and-effect relationships.

Experimental group

The group in a study that receives the treatment or manipulated variable.

Control group

The group in a study that does not receive the treatment, serving as a baseline for comparison.

Random assignment

The process of assigning participants to experimental or control groups by chance to reduce bias.

Double-blind experiment

A research design in which neither the participants nor the researchers know who is in the experimental or control group, preventing bias.

Placebo effect

A psychological response in which participants experience changes simply because they believe they are receiving a treatment.

Independent variable

The factor that is manipulated by the researcher to examine its effect.

Dependent variable

The outcome or response that is measured in an experiment to determine the effect of the independent variable.

Confounding variable

An extraneous factor that may interfere with the results by influencing both the independent and dependent variables, however it is not studied in the experiment.

Validity

The extent to which a test or study accurately measures what it claims to measure.

Reliability

The consistency of a research study or measurement over time and across different trials.