Deen is a gifted classroom teacher who is at the cutting edge of research in first language acquisition, which he communicates effectively to both graduate and undergraduate students. His students are told that nothing he says is beyond reproach, and it is their right and duty to challenge him. Thisprinciple of teaching has paid tangible dividends in the form of a substantial increase in the number of his graduate students presenting papers at prestigious national and international conferences. A colleague observed, "He is, in short, the consummate ʻall-rounder.‘"