This digest examines research on indicators of teacher quality. While research on the value of a teacher's advanced degree is mixed, all studies suggest that teachers with degrees in subjects different from the subjects they teach have little impact on students. There is no strong consensus about the value of pedagogical preparation for teachers, but findings suggest that teachers with advanced degrees in specific subjects can have an impact on student learning in those subjects in certain settings. There is not a strong enough research base from which to draw definitive conclusions about the value of state regulation of the teacher labor market. Findings vary widely regarding the relationship between years of teaching experience and student outcomes. However, it appears that the magnitude of the experience effect, should it exist, is not terribly large. Some studies indicate that teachers who attend more selective undergraduate colleges are more effective in the classroom. The literature on teachers' academic proficiency indicates that measures of teacher academic proficiency represent one of the best predictors of teacher quality. (Contains 16 references.) (SM)