Item components that might contribute to the difficulty of items on the Raven Colored Progressive Matrices (CPM) and the Standard Progressive Matrices (SPM) were studied. Subjects providing responses to CPM items were 269 children aged 2 years 9 months to 11 years 8 months, most of whom were referred for testing as potentially gifted. A second sample containing 147 seventh-grade students, drawn from J. K. Gallini's study in 1983, was used to assess the utility of the equation developed using the first item sample. CPM item characteristics were defined and rated. Rasch item difficulties were used as the dependent variable with misfitting items omitted. All 15 item characteristics were entered in a regression equation using forced entry (multiple "R" of 0.90) and stepwise entry (multiple "R" of 0.88). When the same predictors were used with SPM items, the multiple "R" was 0.69. The poorest prediction occurred for items containing characteristics (such as line thickness) that were not captured by the coding system. The best prediction occurred for items in which the orientation of the figure or options was a crucial feature. Results are discussed with regard to psychological processes and use of item characteristics to create new test items. Two sample test items are included, and two tables and an appendix present data on item difficulties. (SLD)