This paper focuses on the challenge raised by the acquired immunodeficiency syndrome (AIDS) epidemic regarding the need to improve the effectiveness of health communication or education campaigns. The paper discusses the behaviors underlying health information processing and particularly what is called the "knowledge but not behavior-change phenomenon" and the importance of managerial structure in the conceptualization, design, and evaluation of health information or education programs. The paper advances the argument that an integrative model based on systems theory would serve researchers and planners better than micro-level models dealing with Knowledge, Affect, or Practice (KAP) variables, opinion- or attitude-holding, attitude-change processes or even health beliefs taken by themselves. The paper argues that systems theory represents a larger scale theory that offers the potential for integrating smaller theories fruitfully. The latter part of the paper deals with the application of segmentation and Management by Objectives (MBO) principles. Two tables of data are included; 93 references are attached. (RS)