Grunig's decision-situation model is proposed as a comprehensive framework under which various public-relations-related theories may be subsumed. The decision-situation model postulates three dimensions which, taken together, may predict the course of communication behavior: level of involvement, problem recognition, and structural constraints. Grunig and others draw upon a coorientation model to evaluate traditional public relations practices. As with the decision-situation model, many of the more empirical studies of external communication can be incorporated into the coorientation constructs. Ideally, the decision-situation model and coorientation model should work together: the former to prescribe the scope and direction of a public relations campaign and the latter to evaluate its success. In conclusion, the decision-situation model was found to serve two functions: by identifying those segments of the population most likely to benefit from promotional activities, it can improve the efficiency of public relations campaigns and, by providing a general paradigm for future research in external communications, it represents a first step toward professionalization of the public relations industry. (Author/AA)