How reliable is the Reliable Change Index? Monte Carlo simulation studies of the RCI

A methodological research line using Monte Carlo simulation to stress-test the Reliable Change Index (RCI), a statistic widely used in clinical and psychological research to judge whether an individual has changed meaningfully over time.

In collaboration with Eben Afrifa-Yamoah (Edith Cowan University), this project evaluates the performance of the RCI across conditions of measurement reliability and effect size, asking when the RCI over- or under-detects meaningful individual change, and under what conditions its decisions can be trusted.

A companion study extends this to ask when the RCI fails outright — examining the joint influence of reliability, distributional non-normality, and decision thresholds on RCI-based conclusions. See Publications for forthcoming papers from this line.