A 20-task learning hierarchy for subtraction of fractions was deductively derived using Gagne's task analysis. To test this analysis empirically, composite items were written for each level and administered to students in grades 3-6. Test results were analyzed by the Walbesser Technique and Pattern Analysis; the acceptance levels developed by Phillips and Kane were used as criteria. These analyses yielded ratios for consistency, adequacy, and completeness which were below the acceptance level. The hierarchy was then revised to maximize these ratios, and an index of agreement of .85 was obtained between the expected pattern of responses and the observed level. The investigators note that: (1) results may have been affected by the fact that very few students were able to answer correctly items from the upper levels of the hierarchy; and (2) the study should be replicated using students with a broader range of abilities and ages. (SD)