UEL Clinical Psychology (ClinPsy) Screening Practice Test 2026 - Free ClinPsy Practice Questions and Study Guide

Within-subjects designs require participants to experience every condition, so the order in which those conditions are presented can shape responses through practice, fatigue, or carryover effects. If counterbalancing isn’t used, these order effects can distort differences between conditions, making it hard to tell whether changes are due to the manipulation itself or to the sequence in which tasks were done. Counterbalancing spreads any order-related influence across conditions, so it cancels out at the group level and the results reflect the true effects of the conditions. In designs where different participants experience each condition (between-subjects and matched-pairs), there isn’t a within-person sequence to confound, so order effects aren’t a concern in the same way. Factorial design is just a framework for examining multiple factors and can be implemented in either style, but the vulnerability described is most pronounced when the same participants encounter all conditions.