Test-Retest Reliability of the WB6Dim Digital Well-Being Tool: A 3-Day Interval Study

The first validation study of the WB6Dim instrument (NCT07301879) established strong internal consistency and convergent validity across N=295 participants. Test-retest reliability was assessed over a 14-day interval on N=92 usable pairs, yielding preliminary ICC estimates ranging from .49 to .77. However, the 14-day interval is methodologically suboptimal for a dynamic monitoring tool: real-life events occurring during two weeks cannot be distinguished from instrument instability, and confidence intervals were wide due to the limited number of pairs. The present study addresses these limitations through three improvements. First, the interval is reduced to 3 days, substantially reducing contamination risk while avoiding memory-based response bias. Second, a contamination control question is administered at T2 to identify and exclude pairs where a significant life event occurred. Third, the target of N=220 usable pairs produces 95% confidence intervals with maximum width of .20 across all dimensions, meeting the precision threshold for definitive psychometric publication. Only the 28 WB6Dim items are administered, with no additional gold-standard scales, reducing response burden to approximately 3 minutes per session. Participant matching is performed via email address.