This paper provides a conceptual definition and model of self-presentational behavior. Self-presentation is defined as the attempt to control self-relevant images before real or imagined others. Several aspects of the definition are discussed along with the notion that people's self-presentations represent the choice of the most desirable images from sets of mutually exclusive alternative images. Factors that influence the desirability of an image are categorized into four components which provide the specification of the model, including: (1) the attractiveness of an image (A); (2) the perceived probability that the image describes the image object (P); (3) the perceived probability that the image is inaccurate (I-P); and (4) the expected value of erroneously attaching an image to an image object (E). These components are explained in great detail and used to create a formulation, D (desirability)=P(A) + (I-P)E, which allows the model to be applied to self-presentations, self-beliefs, and beliefs in general. Several implications of the formulation for self- and interpersonal beliefs as well as for self-presentations are also explored. (NRB)