ABSTRACT
Researchers in all fields need to make and revise classifications continuously. For example, researchers in psychiatric field need to make classification of mental patients based on psychiatric test scores in order to improve their understanding of mental illness and plan for its treatments. The proportional incidence of one symptom or another indicates whether it is a characteristic feature of the disease or not. The identification of signs and symptoms of a disorder or syndrome is the major concern of psychiatrists. Inadequate parental control of hyperactivity children is found by chance, and it is found in almost every case of conduct disorder children.
