In the terminology used in the UGC NET June 2013 re-conducted Paper I…

Concept

Historical examination questions can use source-specific labels for experimental arrangements. A previous-year question must therefore be read with its exact printed option set and the examination authority’s final key.

The labels should not be silently normalised to a different technical term; the governing check is whether the original paper and its official key agree on the intended classification.

Application

The original Set-W paper prints “Rational group experiment” exactly, so it is not an altered form of “Rotational group experiment.” For this source-specific item, the official post-grievance key excludes “Residual group experiment” from the listed experimental-method types.

Contrast

• Single group experiment: one participant group follows one planned intervention and measurement schedule.

• Parallel group experiment: distinct participant groups proceed through concurrent study arms.

• Rational group experiment: this is the exact source-specific label printed in the original Set-W option set; it must not be replaced by a different word.

Cross-check

The official Set-W question paper confirms all four displayed values, and the official post-grievance answer key identifies “Residual group experiment” for question 47.

Therefore, under the source terminology stated in the question, the required answer is Residual group experiment.