Though the oral proficiency interview (OPI) rates the examinee's overall language proficiency in face-to-face interaction, the rating is based solely upon the evaluation of the examinee's contribution in isolation. No attempt is made to evaluate conversational skills in interaction. A criticism that has been made of the OPI is that the format is not appropriate for the evaluation of such interactive dialogue events. As one way to enhance the understanding of language proficiency in interaction, this study undertakes a step-by-step analysis of negotiation of meaning of eight examinees in four different proficiency levels obtained from a OPI training workshop. More specifically, the study examines negotiation sequences, focusing on the interactional modifications used by the interviewers and communication strategies used by the examinees. The study explores how these problem-solving behaviors reflect the examinees' conversational skills in interaction, and argues that the OPI evaluation protocols should be amended to explicitly take such skills into account. (Contains 11 tables.)