Research on the Rasch model of test and item analysis was applied to tests constructed from item banks for reading and mathematics with respect to five practical problems for scaling items and equating test forms. The questions were: (1) Does the Rasch model yield the same scale value regardless of the student sample? (2) How many students are needed to accurately scale a test: (3) Are the scale values for items equal interval? (4) Does the Rasch produce equal achievement levels for the same students on different tests? (5) Does an item receive the same scaling regardless of the other items on the test? All of the research, including replications of three of the studies, supported the usefulness and accuracy of the Rasch model. It was judged that 200 students were sufficient to produce reliable item scaling. (CTM)