Validity
Validity is an important criterion of any observations.
Three types of validity:
Threats to validity
Threats to internal validity
• confounding
• experimenter bias
Techniques to increase internal validity
• random assignment
• experimental control
• double-blind technique
• automated data collection
Threats to construct validity
• confounding
• participant reactivity
• random error
Techniques to increase construct validity
• operational definitions (decrease random error)
• research protocols (decrease random error)
Threats to external validity
• important psychological processes are not represented
• big differences in processes between various subject populations
Techniques to increase external validity
• replication