To determine the number of distinct words in printed school English, a study analyzed a 7,260 word sample from the "Word Frequency Book" prepared by J. B. Carroll, P. Davies, and B. Richman. Projecting from the sample to the total vocabulary of school English, the best estimate was that it contained about 88,500 distinct words. Furthermore, for every word a child learned, it was estimated that there were an average of one to three additional related words that should also be understandable to the child, the exact number depending on how well the child is able to utilize context and morphology to induce meanings. Based on this analysis, a reconciliation of estimates of children's vocabulary size was undertaken. It showed that much of the extreme divergence in estimates was due to the definition of "word" adopted. The findings indicate that even the most ruthlessly systematic direct vocabulary instruction could neither account for a significant proportion of all the words children actually learn, nor cover more than a modest proportion of the words they will encounter in school reading materials. (Author/HOD)