This article explored the differences between expert and novice teachers' perceptions and interpretations of problematic classroom events. The authors identified a number of differences in the way experts and novices perceived, interpreted and explained the problematic situations with which they were presented. The findings reveal that the novice teachers expressed significantly more visual perceptions. The experts, however, offered significantly more interpretations: they provided inferences about students, inferences about the teacher, and explanatory and/or reasoning statements. The authors conclude that novice teachers perceive students as key contributors to the problems which arise and escalate. However, the experts share their reasoning, explicating how and when problems emerge.