This study examined the convergent validity of a computerized use of time diary (MARCA) relative to pedometry. Participants aged 9–16 years wore a pedometer and completed the MARCA. Comparing pedometer data and self-report data collected for the same day (n = 297 participants), the correlation (Spearman’s rho) with PAL was 0.54 and with MVPA was 0.50. Comparing mean daily step counts over 6–7 days with averaged self-report data collected on different days (n = 1713 participants) Spearman’s rho for PAL was 0.45 and for MVPA was 0.44. Thus, the MARCA showed validity similar or superior to most self-report instruments for young people.
Olds, Dollman, and Maher are with the Sansom Institute, Div. of Health Sciences, University of South Australia, Adelaide SA 5001, Australia. Ridley is with the School of Education, Flinders University, Adelaide SA 5001, Australia.