Estimating reactivity in direct observation studies of health behaviors

Direct observation techniques are increasingly being used to measure human behavior as part of health research and intervention studies. One problem with this approach that has not been well-explored is the effect of the observer's presence on the behaviors being observed, the reactivity effect. This article examines reactivity effects in a direct observation study of child care and feeding practices in rural Nepal. Trained field workers conducted day long structured observations in 160 households, seven times per household. Our results indicate that the first day of observation is more reactive than later days. A number of individual behaviors changed in frequency from observation day to observation day, including punishment of the child and method of serving food to the child. Observation days with higher levels of reactivity showed an increase in the number of positive health behaviors and a decrease in the number of socially negative behaviors. We conclude that the validity of direct observation studies of behavior can be enhanced by examining and controlling for reactivity effects.