Quasi experimental design characteristic – UGC NET Question

A quasi-experimental design includes an active intervention or manipulation of an independent variable but does not use full random assignment of participants to groups. As a result, groups may differ on important characteristics before the treatment, making causal inferences more tentative. Such designs are common in real-world settings where randomisation is impractical or unethical. Therefore, the design described in the stem is known as quasi-experimental.

Option A:
Pre-experimental designs often involve one-group pre-test–post-test structures or static group comparisons with very weak control of threats to internal validity. They are usually considered methodologically weaker than quasi-experiments and may lack proper comparison groups. So pre-experimental is not the best completion.

Option B:
Correlational designs examine relationships between variables without manipulation, using naturally occurring variation. They do not involve assigning a treatment or intervention, so they do not match the stem.

Option C:
Ex post facto designs investigate potential causes after outcomes have occurred, without manipulating the independent variable. They are retrospective and non-manipulative, which differs from the active intervention element in quasi-experiments. Hence, ex post facto is not appropriate here.

Option D:
Option D, quasi-experimental design, specifically denotes studies where the researcher manipulates the treatment but uses existing or non-random groups such as intact classes. This fits the question exactly, so it is correct.