ABSTRACT
We analyze interviews of graduate student instructors to describe beginning instructors' interpretations of and reactions to student behavior. The emphasis of this article is on student behavior that the instructors regarded as direct challenges to classroom authority. The interpretations and responses of beginning instructors are contrasted with expert advice offered in teaching literature. We identify priorities that influence instructors' interpretations of and responses to these challenges. These priorities are: (1) protecting evaluative authority or credibility as assessor, (2) following the regulations of the course, (3) protecting rights to make pedagogical decisions, (4) protecting credibility as a person that students can be confident learning mathematics from, and, (5) protecting a basic level of respect for self and others. We suggest guidelines for course directors and faculty mentors to help beginning instructors learn from the difficult situations that they may encounter.