Validity

Validity in Psychology

When an assessment tool measure what’s is designed to measure

(are we really measuring what we think we’re measuring?)

Internal Validity

The extent to which a study establishes cause-and-effect relationship between the independent and dependence variables – how confident is the researcher that the observed effects are due to the manipulation of the IV and not some other extraneous variable

example question: Did the therapy reduce anxiety, or was it just the placebo effect?

External Validity

The extent to which the results of the study can be generalised to other situations, people, settings and measures. Researchers aim for high validity so that their findings are relevant and useful in real-world situations.

example question: Does the study of anxiety only show a benefit in the lab setting? If so then the findings might not generalise to real life anxiety management

Types of External Validity

• Population Validity

• Ecological Validity

Population Validity

concerns the extent to which the results can be generalized to different groups of people (population)

Ecological Validity

concerns the extent to which the results can be generalised to different settings and situations (setting)