In keeping with clinical/consulting psychology as a health care profession and in order to provide proper planning, services are normally preceeded by an assessment period usually lasting one to three sessions. As in most situations, when one seeks out assistance, a wise service provider will assess and evaluate to best determine what is actually needed before providing care. Just as is the case in medicine, an individual may have signs or symptoms which cause concern but a professionally trained person is required to actually make a diagnosis and recommend treatment. Psychologists most frequently have enhanced skills to assess mental and emotional difficulties; having been educated and gaining experience in the application of many different diagnostic techniques, including psychological testing with standardized instruments. After some time a psychologist gains the ability to rule out a number of diagnoses while settling on a conclusion that best fits the persons self report and their demeanor, without having to perform complex and costly test procedures to arrive at these determinations.
The final conclusion and recommendations may or may not coincide with what an individual and the "Google god" believes is wrong and what he or she thinks is needed. But, as a result of the initial consultation(s), a good working relationship will mean that both parties feel comfortable with the assessment result and recommended course of action. Whenever the transaction involves more than two people, such as in the case of children and adolescents, families, courts, organizations, insurance sponsored interventions etc, the situation becomes a bit more complicated. However, there is no "one size fits all" approach and each individual's situation is understood as being unique, regardless of the "label" or diagnosis. Some, but not all, of what is being assessed in these initial encounters will comprise one's ability to manage his or her everyday affairs, the level of discomfort, the types of symptoms that are being experienced, the frequency and the duration of the discomfort, contributing factors from the environement, a report of the current physical condtion, the overall structure of the situation within which the individual finds him/her self or the grouping finds itself, how the capacity to think and feel and maintain physical health is affected, etc.