Chapter 10 Nonexperimental and Quasi-Experimental Designs

Flashcards covering key vocabulary and concepts related to nonexperimental and quasi-experimental research designs, including nonequivalent group, pre-post, and developmental designs.

True Experiments

Emphasize internal validity by using random assignment and controlling study procedures to manipulate the independent variable.

Quasi-Experiments

Emphasize external validity, use existing groups, and select but do not manipulate the independent variable.

Non-Experiments

Emphasize external validity, make minimal attempts to control confounds, and are often ex post facto.

Major diffs True experiments

prioritize internal validity through controlled conditions.

Major diffs Quasi- and non-experiments

have less internal validity but greater external validity due to naturalistic settings.

Research Questions of
Quasi/Non-Experiments 1

The differences in existing groups or
programs (e.g. military service,
psychotherapy program

Research Questions of
Quasi/Non-Experiments 2

The effects of events over time (e.g. pre-
post treatment)

Research Questions of
Quasi/Non-Experiments 3

The differences among groups as a
function of development (e.g. cohorts)

Nonequivalent Control Group Design

A quasi-experimental design with experimental and control groups where subjects are NOT randomly assigned.

Mixed Factorial Design (Non-manipulated Variable)

A type of nonequivalent control group design with more than one IV, where subjects aren't randomly assigned for one factor.

Differential Research Design

A non-experimental design that compares pre-existing groups to establish a difference; similar to correlational studies with no intervention.

Posttest-Only Design

A non-experimental design that compares pre-existing groups after treatment, with no baseline measurement.

Pre-Post Design

A non-experimental design using the same group, compared over time, before and after a manipulation without a control group.

Interrupted Time-Series Design

A quasi-experimental design using the same group, compared over time before and after a manipulation, attempting to control confounds (event usually not controlled).

Repeated-Treatment Designs

A quasi-experimental design using the same group, with baseline, treatment, withdrawal, and re-treatment, resembling single-subject ABAB design.

Cross-Sectional Study

A non-experimental developmental design that studies different age groups at the same time.

Longitudinal Study

A non-experimental developmental design that studies the same cohort over time.

Cross-Sequential Design

A non-experimental developmental design that studies multiple cohorts over time, combining cross-sectional and longitudinal aspects.

Cohort Effect

Differences in groups due to historical, cultural, or social events, which can confound age in cross-sectional studies.

Secular Trend

A change taking place in the general population over time, potentially confounding longitudinal studies.

Time-Lag Effects

The result of comparing subjects of the same age at different times in a cross-sequential design.