Twenty-one criteria for assessing communication effectiveness in organizations provide the basis for discussion in this document. Grouped under the general heading of communication rules, the criteria are described according to five categories: structure, messages, media, communicator, and potpourri (factors that affect the decision making of communicators but are not directly related to communication). The major research literature regarding each criterion is identified by author and discussed in terms of effective and ineffective communication, in an attempt to define "communication effectiveness" in operational and practical terms. The paper concludes with a suggested outline of the steps involved in developing this initial effort--the derivation of propositions or assertions, operationalization and measurement, and research that will provide empirical evidence about the reliability, validity, and value of the criteria. An extensive bibliography is appended. (Author/MAI)