In this technical report, we describe the development of cognitive diagnostic test items that form the basis of the diagnostic system for Project DIVIDE (Dynamic Instruction Via Individually Designed Environments). The construct underlying the diagnostic test is division of fractions. We include a description of the process we used to identify the cognitive attributes for division of fractions. We present the hierarchical association between attributes that lead up to mastery of the domain. Finally, we describe item writing procedures and evidence for technical adequacy of the resulting item bank. Appended are: (1) Biographies of Researchers and Consultants; (2) Attribute List; (3) Adjacency Matrix; and (4) Item/Person Map.