The doctor's training is focused on evaluating the state of the whole individual with a view to prescribing treatment. Data collection, by contrast, requires a level of precision and attention to minute detail that is irrelevant in clinical diagnosis and curative care. This difference is a source of misunderstanding that tends to lead to high levels of recording error. Data collection also is the tedious and repetitive type of work best assigned to lower-level but welltrained and standardized technicians. Physicians are indispensable, however, for diagnosis of unusual conditions and for emergency treatment of severely ill infants.
Mortality rates are difficult to relate to nutritional status.
In most cases official figures cannot be trusted to apply to a given study population. The most common source of error stems from failure to report either the birth or death of children who die shortly after they are born at home. The different disciplines relating to positive deviance have different vocabularies, theoretical assumptions, and standards for quality control. For these reasons it is desirable to have strong leadership for such teams. Alternately, a strong project director or contract manager with a technical background may provide sufficient leadership to ensure that principal investigators from different disciplines integrate their work effectively.