Designed to determine how well the student materials and teachers' guides of commercial spelling programs inform teachers of and reflect important spelling research, present management systems adaptable to individual student needs, provide strategies eliminating unnecessary or nonspelling instruction, and maximize the provisions for individual student differences, the Spelling Program Effectiveness Rating Scale was applied to 10 nationally known spelling programs and two programs designed on research-supported strategies. Evaluation results implied that (1) programs with research-supported and nonresearch-supported strategies differed widely; (2) teachers' guides generally failed to report on the literature of spelling, the criteria for word selection, or any empirical research on the effectiveness of their programs; (3) most manuals did not provide clear procedures for handling individual student differences; (4) student materials contained a wide variety of word study activities that were not supported as spelling strategies; and (5) only three of the evaluated programs received an overall rating that was higher on the positive scale than the negative scale. (MM)