1. Goal of Psychology: to determine the Underlying “laws” of behavior.
External Validity
Goal of Psychology: to determine the
Underlying “laws” of behavior.
External Validity – the extent to which the
results of an experiment can be applied to and across different persons, settings, and times.
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2. Population Validity – ability to generalize results from the sample to a larger population.
Random Selection – from a population should insure generalization to the experimentally accessible population.
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3. Target Population - larger population to which results are generalized.
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4. ALL PERSONS WITH DEPRESSION
Persons Diagnosed
Willing
Control
Studied
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5. Ecological Validity: extent to which results can be generalized across settings or environmental conditions.
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6. Temporal Validity – generalizability across time. Seasonal Variation
- fixed-time variation
- variable time variation
Cyclical Variation
Personological Variation
e.g., are you planning a mid-life
crisis?
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7. Treatment Variation Validity
- Degree the results of a study can be generalized across variations in the treatment
Outcome validity
- Degree to which the results of a study generalize across related dependant variables.
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8. Relationship between Internal & External Validity
To obtain high Internal Validity we often create very artificial study settings.
To establish external validity we often need to determine if the finding applies across setting, locations, cultures etc.
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9. (ie14)