The purpose of this study was to investigate undergraduate teaching assistant (UTA) competence and character and its relationship to learning in the basic communication classroom. Also of interest were the specific UTA communicator behaviors that increase or decrease student perceptions of competence and character. Students responded to a survey which asked them to rate (1) either their UTA's or a university faculty's credibility; (2) their own learning, and (3) describe behaviors that contributed positively and negatively to their teacher's credibility. On the whole, results from this study indicate students perceive UTAs as credible, and UTA credibility is strongly related to student learning. Qualitative analysis revealed UTA communication behaviors that contribute to and detracted from their credibility. Interestingly, UTA scores for credibility were slightly higher than university faculty scores for credibility. Implications for UTAs and UTA training and recruitment are discussed. Contains 21 references. Two tables of data are appended. (Author/RS)