DSM-IV seems clear in its criteria and in its descriptive, a theoretical approach. This may lead to a false sense of security in practicing diagnostics. The most difficult part of the diagnostic process is recognizing specific behaviors and the degree of impairment they may represent. Usually, an extensive combination of clinical train ing and experience is required to attain the degree of expertise needed to apply a diagnostic system. For childhood disorders, intensive exposure to individuals with specific handicaps and spe cific behavioral disturbances at all ages-from infancy to early adulthood-is essential for mastery of diagnosis.