The main internal validity problem of the static-group comparison ...

[schs14]

The main internal validity problem of the static-group comparison design is
 
  a. observed posttest differences may be due to preexperimental differences between the groups rather than to the experimental treatment.
  b. the interaction between the experimental and control treatments.
  c. the pretest may sensitize subjects to the experimental treatment.
  d. the matching procedure may result in the loss of too many subjects and thus introduce bias.

Question 2

Distinguish between concurrent and predictive evidence of validity.
 
  What will be an ideal response?

[katieost]

Answer to Question 1

A

Answer to Question 2

Concurrent evidence is the relationship between scores on a measure and a criterion obtained at the same time. Predictive evidence is the relationship between scores on a measure and a criterion available at a future time.