Variables and Research Design

These flashcards cover key concepts in variables and research design, focusing on different types of variables, validity, and research methodologies.

Independent Variable (IV)

The variable that is manipulated or controlled in a study to observe its effect on the dependent variable.

Dependent Variable (DV)

The variable that is measured in an experiment; it is affected by changes in the independent variable.

Extraneous Variable

A variable that is not the focus of the study but could influence the outcome if not controlled.

Confound

A specific type of extraneous variable that alters the relationship between the independent and dependent variables.

Causation

The action of causing something; in experiments, it refers to a situation where a change in IV leads to a change in DV.

Internal Validity

The extent to which a study can demonstrate that the independent variable caused changes in the dependent variable.

External Validity

The degree to which the results of a study can be generalized to other contexts, populations, or times.

Quasi-Experimental Design

A type of research design that seeks to evaluate interventions but lacks random assignment to groups.

Non-Experimental Design

A study design that does not involve manipulation of independent variables and therefore cannot establish causation.

Covariate

A variable that is related to the dependent variable and can be controlled to clarify the relationship between the IV and DV.

True Experimental Design

A research design characterized by random assignment to conditions and manipulation of the independent variable.

Sequence Effect

A type of bias in within-subjects designs where the order of conditions can affect participants' responses.

Control Group

A group in an experiment that does not receive the treatment or intervention, used for comparison with the experimental group.

Between Subjects Design

An experimental design where different participants are assigned to each condition.

Within Subjects Design

An experimental design where the same participants experience all conditions.

Factorial Design

An experiment that investigates the effects of multiple independent variables on a dependent variable.

Post-Test Only Design

An experimental design where data is collected after the intervention without pre-testing participants.

Pre-Test Post-Test Design

An experimental design that measures the dependent variable before and after the intervention.

Maturation Effect

The changes that occur in participants over time that can affect study results, independent of the treatment.

Testing Effect

When the act of taking a test affects the performance on subsequent tests.

Attrition Threat

A threat to internal validity that arises when participants drop out of a study at different rates.

Statistical Power

The probability that a test will correctly reject a false null hypothesis, indicating the likelihood of detecting an effect.

ANOVA (Analysis of Variance)

A statistical method used to compare the means of three or more groups.

Regression Analysis

A statistical technique for examining the relationship between one or more independent variables and a dependent variable.

T-Test

A statistical test used to compare the means of two groups.

Correlation

A statistical measure that describes the extent to which two variables change together, but does not imply causation.

Construct Validity

The degree to which a test measures what it claims to measure.