Methodological considerations for ecological momentary assessment measures of task-unrelated and freely moving...

Numerous studies examining task-unrelated and freely moving thoughts have employed ecological momentary assessment (EMA) paradigms to assess these constructs in daily life. However, there is substantial variability across studies regarding sample size, duration of the study, number of probes per day, and compliance rates. These methodological differences leave many questions unanswered about their influence on the psychometric properties of assessments for these thought dimensions and the best practices for EMA studies in this field. To address these gaps, we conducted a four-week EMA study assessing several dimensions, including task-unrelated thought, freely moving thought, and affective valence. We found that individuals' self-reported thoughts became more reliable over time. Our results also demonstrated how people reported these constructs and how the relationships between them changed with study duration (which remained consistent irrespective of compliance rate) and, to a lesser extent, sample size and number of probes per day. Taken together, our study established the impact of different methodological variations in EMA designs on the psychometric properties of measures of thought dimensions and their associations with affective valence. We offer recommendations for choosing the optimal sample size, study duration, and frequency of daily probes for EMA studies of these dimensions.