With the emergence of big data science, the question how we can easily collect meaningful information about circadian clock phenotypes in large human cohorts imposes itself. Here, we describe potentials and limitations of using questionnaires, specifically the Munich ChronoType Questionnaire (MCTQ), to characterize such circadian phenotypes. We also discuss scenarios when alternative methods might be more appropriate.
Keywords: Chronotype; Circadian disruption; Diurnal preference; Entrainment; Misalignment; Phenotyping; Proxy; Sleep; Sleep timing.