Style and expression is one of the four dimensions of the assessment of text quality. Yet, in contrast to normative language correctness, (relatively) clear rules can only be used to a limited extent. Where precise criteria are missing, however, both the acquisition and the development of the necessary skills by the students and the evaluation by the teachers become difficult. On the basis of selected student performances of the text type opinion speech from the text type catalogue for the written matriculation examination in Austria and the requirements for linguistic expression defined for it, linguistic features observed by different teachers, their evaluations, and the understanding of style that guides these assessments are examined.