External validity in research – UGC NET Question

Statement D is wrong because convenience sampling does not guarantee high external validity; it often leads to biased samples that limit generalisation. Statements A, B, C and E are correct: external validity concerns generalisation, narrow or atypical samples restrict it, replication strengthens it and realistic settings can enhance ecological validity. Hence, the only wrong statement is D.

Option A:
Option A is incorrect because it also labels A, which properly defines external validity, as wrong along with D. Treating A as incorrect misrepresents a basic concept in research design.

Option B:
Option B is wrong because it groups B with D as wrong, even though B accurately describes how an atypical sample can limit generalisability. Misclassifying B obscures a key threat to external validity.

Option C:
Option C is also incorrect because it treats C, which rightly notes the value of replication, as wrong. Replication is a standard strategy to test the robustness of findings across contexts.

Option D:
Option D is correct as it singles out D as the only statement that wrongly exaggerates the merits of convenience sampling for generalisation, while implicitly accepting the rest as accurate.