Abstract
Ecological momentary assessment (EMA) studies offer a unique access to within-person variability processes. Despite their widespread use in psychological research, we know very little about the factors that determine their successful application. This study combines time- and event-contingent assessments to examine the reliability of event-contingent reporting, person-level predictors of compliance, and qualitative differences between assessment methods in a 14-day EMA study of daily stressors. Our results indicate that stress beliefs, personality and mental health are associated with compliance and event-contingent reporting. There was no evidence that event-contingent reports might have been omitted in high-stress situations. On the contrary, event-contingent assessments were generally more extreme in terms of stress-intensity, affect and somatic symptoms. Event-contingent assessments may thus capture a more extreme subset of events and certain types of participants may be particularly likely to self-initiate these assessments. We discuss implications of these findings for the design of future EMA studies.