CH10 Simple Experiments Cards

Independent Variable (IV)

The variable that is manipulated by the researcher in an experiment.

Dependent Variable (DV)

The variable that is measured in an experiment to assess the effect of the independent variable.

Control Variable

Any variable that an experimenter holds constant to prevent it from influencing the results.

Design Confound

A second variable that varies systematically along with the independent variable and provides an alternative explanation for the results.

Selection Effect

Occurs when participants in one level of the IV are systematically different from those in other levels.

Order Effects

Changes in participants' responses resulting from the order in which conditions are presented.

Posttest-Only Design

An experimental design where participants are tested on the dependent variable only after exposure to the independent variable.

Pretest/Posttest Design

An experimental design where participants are tested on the dependent variable before and after exposure to the independent variable.

Construct Validity

Refers to how well the variables are measured and manipulated in a study.

Statistical Validity

Describes how well a study's statistical analysis supports its conclusions regarding significance and effect size.

Internal Validity

The extent to which a study can rule out alternative explanations for its results.

External Validity

The degree to which findings from a study can be generalized to other populations, settings, or times.

Random Assignment

The process of randomly assigning participants to different experimental conditions to control for selection effects.

Matched Groups Design

A design where participants are matched on a certain variable and then randomly assigned to different conditions.

Covariance

The degree to which changes in one variable correspond to changes in another variable.

Temporal Precedence

The principle that the cause must precede the effect in time.

Causal Claim

A statement asserting that one variable causes a change in another variable.

Pilot Study

A preliminary study conducted to test the feasibility, time, cost, and adverse events involved in a research proposal.

Fatigue Effect

A type of order effect that occurs when participants' performance deteriorates due to fatigue over repeated testing.