How do people interpret and respond to self-report sitting time questionnaires? A think-aloud study

Sedentary behaviour research to date has been predominantly based on self-reported sitting time, yet little attention has been paid to how respondents interpret sitting questionnaire items. 25 office workers participated in qualitative, ‘think-aloud’ interviews, describing their thoughts while completing 43 items derived from 9 existing questionnaires. Inductive Thematic Analysis identified four potential interpretation or response problems: misinterpretation and uncertainty; the mental calculation process involved in formulating responses; self-presentation concerns; and the affective and motivational impact of questionnaire completion. Results not only show that lay representations of sitting may diverge from those of researchers, but also highlight potential errors and biases encountered when generating sitting estimates. Additionally, reporting sitting may generate a desire to reduce sitting time. Findings suggest that domain-specific measures that estimate sitting across different settings may better correspond with participants’ perceptions. Future research should investigate the potential for sedentary behaviour questionnaire completion to change behaviour.