Introduction to neuropsychiatric decision making: binary diagnostic tests

This is the first in a series of articles that provide a guide to the understanding and effective use of diagnostic tests in clinical and research endeavors. In this article, we briefly describe some general properties of diagnostic tests. We then focus our attention on binary diagnostic tests, i.e., tests that have only two outcomes, positive or negative. Even though most medical literature assumes that all diagnostic tests are binary, truly binary tests are actually quite rare. Studying them, however, provides a convenient way to familiarize ourselves with important decision-making nomenclature.