ABSTRACT
Many of the origins of assessment came from attempts to address wartime needs. Since the 1980s, there has been a general decline in the frequency with which clinical assessment (and psychotherapy) are conducted by clinical psychologists, due to managed care and cost containment. Many errors of pseudo-prediction are relevant to clinical assessment, such as confusion of inverse probabilities and regression to the mean.
Prevalence is the proportion of the population that has the condition a given point in time, whereas incidence is the rate of occurrence of new cases. Point prevalence is the proportion of the population that has the condition at a single point in time. Lifetime prevalence is the proportion of the population that will ever have a condition at any point in their lifetime. The positivity rate is the proportion of tests that are positive.
Signs are observable features of a disorder. Therefore, signs can be perceived by a clinician. By contrast, symptoms are unobservable manifestations of a disorder that can only be perceived by the client. A syndrome is a collection of signs and symptoms that co-occur and may reflect a particular disorder.
