Table 1.

Response model framework

Comprehension	Recall	Judgment	Response mapping
Reflects the encoding process: participants had problems understanding, or a misunderstanding of, a word, phrase or response option OR participants understood the question in a different way than the measure intends the question to be understood (often closely linked to judgement)	Refers to the retrieval process—including using the wrong time frame for retrieval and problems remembering relevant information	Problems with judging the information retrieved, including retrieving irrelevant information or assessing the information inadequately—leading to under or over-reporting of health state (often closely linked to comprehension)	Problems with the response categories including not liking the options or inappropriately applying them e.g., choosing two or not wanting to choose any OR stated answer (verbal protocol data) misaligned with chosen answer (survey response data)