This article defines a performance objective as an answer to the questions of who does what, how well, and under what conditions. Three components usually considered mandatory for a performance objective are the action or behavior in which the person engages to demonstrate that he has learned what he was expected to learn, the condition under which he is to carry out the action, and the minimum standard or criteria which he is expected to meet to prove that he really did learn at an acceptable level. After defining and giving examples of performance objectives, the publication discusses the method of writing a performance objective, producing usable objectives to guide learning, student validation of objectives, domains of learning, and objectives for personnel evaluation. (Author/DN)