Indication
Direct observation measures the type, duration and frequency of activity in real time; the intensity of activity is problematic as it relies on subjective classification which is an issue in mid ranges of intensity especially. The method also allows contextual and environmental data to be collected.
Direct observation can only measure physical activity in controlled environments such as school break times and for short-term validation studies. As the intensity of activity is not measured the method cannot be used to estimate energy expenditure.