Rapkin and Schwartz draw attention to “cognitive appraisal” as foundational to understanding response shift. Their argument is grounded in the theoretical premise that response shift arises from a process of cognitive change in how people interpret and respond to items for measuring quality of life and other patient-reported outcomes. In this invited response, I relate the notion of cognitive appraisal to theoretical perspectives of measurement validity that focus on inferences, actions, and decisions made on measurement scores [
1]. From this point of view, response shift research on cognitive appraisal can be viewed as a form of measurement validity evidence, where the goal is to arrive at justifiable inferences about the meaning of variability in longitudinal change of measurement scores [
2]. I conclude with a discussion of methods for examining individual differences in response shift, including a novel approach that involves the use of latent class models. …
