Statistical Validity

Question 1

What is construct validity?

Answer 1

Pertains to the interpretation or basis of the effect that was demonstrated in an experiment

Question 2

What are the threats to construct validity?

Answer 2

Demand characteristics
Expectations of the experimenter
Attention to the clients

Question 3

What are demand characteristics? (Orne, 1962)

Answer 3

Factors associated with the experimental situation that may contribute to the results
Information conveyed to the prospective participants prior to their arrival, instructions, procedures, and any other features of the experiment

Question 4

What is internal validity?

Answer 4

Extent to which the experimental manipulation or intervention, rather than extraneous influences, can account for the results, changes or group differences
Good internal validity results in strong evidence of causality

Question 5

What are some threats to internal validity?

Answer 5

Similar experimental conditions
Measurement changes that occur over time
Statistical regression
Previous test exposure
History - internal and external events
Attrition
Selection bias
Maturation

Question 6

What is external validity?

Answer 6

Extent to which the results can be generalized or extended to persons, settings, times, measures, and characteristics than those in the particular experimental arrangement

Question 7

Considerations to external validity?

Answer 7

Participant reaction to the experiment - collaborative, contradict, faithful, apprehensive
Limitations of sample characteristics
Participant knowledge of being assessed
Novelty effects
Timing of measurement