As a result, agencies and insurance companies are less likely to subsidize this assessment method. Another disadvantage is that the presenting problem simply may not occur during the observation period. Perhaps there is a substitute teacher, the schedule has been changed, the student who bothers him is absent that day, etc. Sometimes a child or adolescent will act differently when she becomes aware that she is being observed. When the naturalistic aspect is lost, the problem behavior often may not surface.
Adults can become self-conscious and act differently knowing that they are being assessed.
To compensate for this reactivity effect, it is sometimes helpful for the professional to observe the individual over a longer period of time since she has a greater tendency to return, in time, to her typical behaviors. Even if the person adjusts his behavior due to being observed, that provides pertinent clinical information. In the clinical assessment process, direct observation is a rich source of information for comprehensive understanding of a consumer's mental health needs. Despite its challenges, it is usually well worth the time and effort.