One-Group Pretest/Posttest Design and Internal Validity

This set of flashcards covers key concepts, definitions, and potential threats related to one-group pretest/posttest design and internal validity.

One-group pretest/posttest design

A research design where a single group is tested before and after a treatment.

Internal validity

The degree to which a study accurately establishes a causal relationship between variables.

Maturation

A threat to internal validity where changes occur naturally over time.

History threat

A threat to internal validity due to external events affecting participants' behavior simultaneously with the treatment.

Regression to the mean

The phenomenon where extreme test scores are likely to be closer to the average in subsequent tests.

Attrition

Participant drop-out from a study, which can affect the validity of the results.

Order effect

A type of testing threat where participants change as a result of repeated testing.

Instrumentation

Changes in the measurement instrument over time that can affect study results.

Observer bias

When researchers' expectations influence their interpretation of results.

Demand characteristics

When participants alter their behavior based on their perceptions of the study's purpose.

Placebo effect

Improvements in symptoms resulting from participants' expectations rather than actual treatment.

Causal relationship

A connection between two variables where one directly affects the other.

Cognitive therapy

A type of psychotherapy that helps patients understand their thoughts and feelings that influence behaviors.

Null effects

Results that show no significant difference or impact from the experimental treatment.

Ceiling effect

A situation where a measurement fails to capture higher scores because it cannot measure beyond a certain threshold.

Floor effect

A situation where a measurement fails to capture lower scores due to a lower threshold.

Manipulation checks

Tests used to verify that the independent variable has been effectively manipulated.

Between-groups difference

The difference between different groups in an experimental study.

Within-groups variability

Variability of measurements within the same group in an experiment.