The author describes eight diagnostic categories which serve as an heuristic approach to diagnosing the client's needs and ability to respond to specific appraoches in therapy/counseling. He reviews classic theories and recent counseling approaches and their variations. The paper focuses on the need to determine individual needs and follow a tailor-made approach according to the obvious personality factors and situation in the initial interview. Diagnosis is a complex problem but thinking aloud (the protocol method) while trying to solve a problem may give insight into the best approach to working with a client or referring the person to someone with a specialized background/facility for dealing with the problem. (SBP)