Fifth, we determined accuracy for vocabulary terms grouped according to Rubenstein and Thompson’s (2002) categories of mathematics-vocabulary difficulty. We conducted this round of item categorization to understand more about which items cause difficulty for students. With the Monroe and Panchyshyn (1995) categorization, more than 60% of terms fell into one category, and information from such a category may not be helpful for educators. Using Rubenstein and Thompson’s categories, most terms (n p 52) were associated with only one category of difficulty, whereas the remaining 12 terms were associated with two or three categories. There were no substantial differences in average accuracy between terms that were in only one category (56.0%) versus terms in more than one category (59.9%) of difficulty. There were, however, differences between individual categories of difficulty.