Handwashing (HW) efficacy studies havetaken the form of randomized controlled trials and theoutcome(s) of interest have primarily been health related.That is, the intervention group, which received HWpromotion, and the control group have been comparedaccording to disease burden. As HW promotion is scaled upand adopted by organizations of varying research capacity,evaluation techniques that are more field-friendly,inexpensive, and readily adaptable are required. Data on HWbehavior may be observed, inferred, or reported. Observeddata may be considered the most objective type of dataavailable for measuring HW behavior. Observations may beconducted using spot checks or continuous observation.Continuous structured observation is frequently used toevaluate HW behavior as well as other hygiene behaviors.This technique consists of the placement of a trainedobserver in a target family's home for several keyhours in the day. The observer can conduct continuousobservation of opportunities for hygiene behaviors and trackwhether or not hygiene behaviors are practiced at thoseopportunities. Observers can also track the quality ofobserved hygiene behaviors, for example the use of soap orash for washing hands.