The book aims to investigate whether the cultural background of nonnative raters has any bearing on how the rating of the oral proficiency interviews (OPI) is conducted within the framework of the national examination in the English language in Estonia. The research comprises the analysis of the rating of twenty video recordings of oral proficiency interviews by two nonnative rater groups - Estonian and Russian ones. The research is complemented by a questionnaire study to examine the rater perceptions of the national examination and the effect of their teaching and rating experiences on the assignment of scores. In spite of the absence of apparent differences in the scores assigned by the raters, the research reveals a substantial difference in regard to the rater behaviour during the rating process as well as their perception of various aspects of the national examination.