The human mind is one of the most advanced machines ever engineered. Understanding it can be a daunting process. The division of an individual’s mental makeup into the conscious, sub conscious and unconscious processes adds to the intriguing nature of human thought, emotion and behavior. Severity of a fracture or diarrhea is easier to estimate than is that of sadness. There is no physical test that measures depression (unlike a hemoglobin analysis in anemia or CT scan revealing a tumor). In these situations, psychometric tests offer a detailed evaluation of thought and emotion even though they seem like abstract concepts that seemingly cannot be quantified.
Psychometric instruments identify thinking styles, emotional processes and behavior patterns that contribute to mental illness. Some tests are diagnostic (they point to a condition that was previously unknown e.g. personality style) while other tests are prognostic (they gauge the severity of depression or anxiety or IQ and watch it change over time). These tests provide vital and fundamental information. Many psychologists do some level of assessment when providing services to patients to assess a particular area of functioning or disability; to help select type of treatment or to assess treatment outcomes; to help courts decide issues such as child custody or competency to stand trial; or to help assess job applicants or employees and provide career development counseling or training.