Forty-one college students participated in a study designed to gather validity and reliability information on a procedure used to measure communication competence, the Communication Competency Assessment Instrument (CCAI). The study, in confirming operationalization validity, found that self-report measures correlated only slightly with observations of students' actual behaviors, while holistic impressions of competence were wholly consistent with the CCAI ratings. In addition, students' persuasive speech grades and instructors' impressions were found to correlate with the CCAI measure, adding to reification, or convergent validity. Elaboration validity analysis discovered that argumentativeness was unrelated to CCAI scores. However, a relationship existed between apprehension, knowledge, and skill, lending credence to the idea that, along with judgments of behavioral appropriateness, impressions of communication competence are also based on perceptions of motivation and knowledge that manifest themselves in actual communication behavior. References, tables, and a figure showing the Communication Competence Self-Report Scale items are appended. (Author/FL)