Teacher knowledge involves a complex network of inter-related domains, including cognition; differences in learning strengths for primary and secondary school students; social and emotional development across the life course; motivation; language acquisition and socialization; curriculum design and assessment; and classroom management. In addition, addressing the problems many students from stigmatized groups bring to the classroom requires an integrated and dynamic response to cultural contexts. The combination of negative societal stereotypes and inequities in social and economic supports for these groups make the application foundational principles for effective learning environments all the more crucial in the quest for equity. These principles include a deep understanding of a variety of social contexts and of subject matter in order to provide for multiple pathways to learning. One partial solution may be to develop internship programs with guided practice with direct feedback. Such a model in education would require transformation of both pre-service training and the conditions of professional practice. (Contains 9 endnotes.)