In this special section, 6 articles address the provocative question of how to determine the boundary between difference and deficiency, for children who differ from the mainstream in some way--language, hearing, cultural background, socioeconomic status, or social understanding. Our commentary considers these articles in light of current models of cultural diversity, raising 4 warning signals about the danger of assuming deficits. Whereas children's school success is understandably a concern, we must be cautious about the known harmful effects of negative labeling and deficit assumptions.