Non equivalent groups design is likely to control which threat?

Non equivalent groups design is likely to control which threat?

(a) History

(b) Differential selection

(c) Additive and interactive effects

(d) Differential attrition

✅ Correct option: (a) History

Explanation :

Nonequivalent groups design uses comparison groups without random assignment. Because both groups experience events simultaneously, history effects are controlled. However, selection and additive effects remain problematic.

10 Related PPSC Facts:

Nonequivalent groups lack randomization. History affects all groups equally. Selection bias remains. Matching reduces selection threat. Quasi-experimental designs use this model. Internal validity is moderate. Pretests help comparison. Attrition affects groups differently. Control groups improve inference. Educational research uses this design.