55 IMPACT OF INTER-INTERVIEWER VARIATION ON ANALYTICAL RATING SCORES AND DISCOURSE IN ORAL INTERVIEW TESTS FUMIYO NAKATSUHARA Abstract Over the last two decades, research has suggested that test performances and test scores are collaboratively achieved through interviewing/scoring processes and that some test-takers might be in unfair situations caused by the paired interviewer. Most of these studies, however, have employed only holistic scores and little has been known about which analytic categories (e.g. pronunciation, grammar, fluency) are vulnerable to what sort of interviewer behaviour. Therefore, it seems meaningful to make explicit which aspects of interviewer variation have an impact on which analytic categories, so that such information could help interviewers’ training by increasing their understanding of the influence of their performance on that of the candidate and on the perception of the second or third raters who later rate audio- or video-recorded tapes. This present research, with the use of an analytical scale, investigates the variability of interviewer behaviour, its influence on a candidate’s performance and consequent raters’ perceptions of the candidate’s ability. The data are collected from two interview sessions involving the identical candidate with two different interviewers, and the video-taped interviews are rated by 22 raters on five marking categories. The result shows that a significantly different score was awarded to ‘pronunciation’ and ‘fluency’ in the two interviews. The reasons for the differences are discussed on the basis of Conversation Analysis (CA) findings and raters’ commentaries. This paper concludes with some suggestions on how the potential unfairness caused by interviewer variability could be solved. 1. Introduction Over the last two decades, a number of studies have analyzed the discourse of various speaking test formats, as the research into the process of the test has been realized as valuable for designing, describing, and most importantly for validating oral proficiency tests (e.g. Young & He 1998, Lazaraton 2002). Accordingly, more attention has been drawn to interlocutor behaviour in oral interview tests, and the variability of interviewers’ behaviour