The major objective of this study was to evaluate the effectiveness of the skill-based Wisconsin Design Word Attack (WDWA) system with severely disabled readers, by comparing a phonetic patterns approach, basal-only approach, and a basal approach combined with the WDWA system. The questions were whether achievement on decoding words in isolation (as measured by the Wide Range Achievement Test) would differ significantly among these three groups and whether subjects (aged seven through twelve) could apply and retain learned skills. Results indicated that there were significant differences in achievement for reading words in isolation, in favor of the group using the basal approach combined with the WDWA system. Other results indicated that this group made greater increases in context reading and that they retained nearly all of the skills mastered. Results also suggested that revisions in the Wisconsin Design resource file might increase its effectiveness with disabled readers and improve its utility in special classrooms. Revision needs, based on classroom observations and teacher interviews, are outlined. (Author/JM)