Daniela Kahlert, Ralf Brand

• The present study examines whether the use of different frequency scales in questionnaires about physical activity influences respondents' own estimation of their activity, as well as subsequent measurements of health- und sport-related cognitions and evaluations. Using a randomized research design we recruited a sample of 118 participants. One group received a high frequency scale for assessing their exercise frequency with the response categories "never", "less often", "once a month", "once a week", or "most days." The other group answered with a medium frequency scale with the alternatives "never", "less often", " once every few months", "once a month", and " once a week or more often." As dependent variables all participants judged the subjective importance of physical activity and their health-related quality of life (WHO-QOL-bref). Results indicate the expected response errors, owing to the fact that using a high-frequency scale produces higher levels of self-reported physical activity (Cramer's V = .30). Corresponding to thisThe present study examines whether the use of different frequency scales in questionnaires about physical activity influences respondents' own estimation of their activity, as well as subsequent measurements of health- und sport-related cognitions and evaluations. Using a randomized research design we recruited a sample of 118 participants. One group received a high frequency scale for assessing their exercise frequency with the response categories "never", "less often", "once a month", "once a week", or "most days." The other group answered with a medium frequency scale with the alternatives "never", "less often", " once every few months", "once a month", and " once a week or more often." As dependent variables all participants judged the subjective importance of physical activity and their health-related quality of life (WHO-QOL-bref). Results indicate the expected response errors, owing to the fact that using a high-frequency scale produces higher levels of self-reported physical activity (Cramer's V = .30). Corresponding to this the subjective importance of physical activity increased (d = .37) and the health-related quality of life was judged to be better (d = .36). Such artefacts might be eliminated by using standardized formulations such as "I exercise... times per week/month for... minutes."…