As one of the federally-funded regional educational laboratories, the Appalachia Educational Laboratory (AEL) is committed to assessing the impact of its products and services on a variety of client subgroups. These include educators and administrators at the elementary, secondary, and higher levels. To address the issue of measuring impact, the AEL identified seven impact categories: (1) overall satisfaction; (2) knowledge and skills; (3) information sharing; (4) use in planning; (5) use in implementation; (6) indirect benefits; and (7) secondary clients' use in implementation. Over a 3-year period, the AEL measured impact with a client questionnaire consisting, in the final version, of 5-item subscales that were administered to 672 individuals in primary client subgroups. Scores from this normative group were converted to percentiles, and mean scores were plotted as profiles for subgroups. Results then reflected specific professional roles and the impacts of the AEL on each. An appendix presents the AEL questionnaire development checklist. (Contains 3 tables, 10 figures, and 12 references.) (SLD)