This research reports on what classroom teachers think about assessment in the visual arts, using interviews with classroom teachers, ethnographic research data and case studies. The author speculates as to the emergence of an "assessment industry" in the sorting, ranking and comparison of students’ artworks by teachers in the local context of the classroom. Emergent categories from the case studies, comprising assessment as authority, rites of passage, a form of exclusion, credentialling, formulas and self-serving activities are placed against traditional assessment theory and alternative proposals. Of particular interest is 'authentic assessment' which provides a point of comparison with the author’s research findings about complexity, teacher autonomy and local views of assessment. This presentation focuses on understanding the procedures and hidden roles that assessment plays in the selected example.