The main goal of the Consumer Assessments of Health Plans Study (CAHPS), which benefits from the complementary strengths of psychometric and cognitive testing, is to develop an integrated set of tested, standardized surveys to obtain meaningful information from health plan enrollees about their experiences. The CAHPS team conducted 150 cognitive interviews across three organizations in different geographic locations using multiple interview methods with different consumer populations. Results show that a modified format is more appropriate when asking about specific aspects of plan enrollees' experiences, whereas a rating format is useful for asking about overall assessments. Specifying a longer reference period is preferable to asking about the most recent visit when capturing experiences with care. The study concludes that cognitive testing was integral to developing and refining the CAHPS instrument, capturing consumers' health care and plan experiences with less response error than one not subjected to such testing.