Does reactivity exist in children when measuring activity levels with unsealed pedometers?

Reactivity refers to a change in activity patterns that results from participants' awareness that their activity levels are being monitored. Previous research has demonstrated that children do not exhibit reactivity when mechanically sealed pedometers are used to measure activity levels. The purpose of this study was to determine whether reactivity occurred when using unsealed pedometers. Forty-five fourth-grade children wore pedometers for 8 days: 4 days sealed and 4 days unsealed. The results suggest that reactivity does not exist when using unsealed pedometers. Accidental resets proved to be a problem; therefore, the use of sealed pedometers might be necessary in order to prevent data losses.