The study was designed to develop a management model for the evaluation of environmental education supplements developed by nonprofit special-interest groups. Naturescope, an interdisciplinary environmental education supplement developed by the National Wildlife Federation (NWF), was used as a vehicle for developing this model. The first component of the study involved the development of the model, while the second component measured evaluation outcomes relative to NatureScope. Working in conjunction with NWF program staff, four issues of NatureScope were randomly selected from the fifteen issues available at the time of the study. Volunteer fifth and seventh grade teachers from Virginia and Georgia were used in the study. A separate knowledge test was developed for each of the four issues. In addition, a 16-item likert scale was developed to measure environmental attitudes. Qualitative information related to the usefulness of NatureScope was collected through a teacher questionnaire. Evaluator interactions with the client, school administrators, and teachers influenced the development and success of the evaluation. The politically-motivated hidden agendas of the client resulted in unexpected modifications to the evaluation process. School administrators displayed a reluctance to permit teachers to participate in the study. Teachers who volunteered expressed concern over a lack of familiarity with the topics and the evaluation process. The evaluation outcomes of the study measured the effects of NatureScope on environmental knowledge and attitudes. Students exposed to Let's Hear It for Herps demonstrated the greatest differences in subject knowledge when compared to the control group. None of the issues had a significant effect on environmental attitudes when compared to the control group. Fifth grade students systematically scored higher than seventh grade students on all measures. Teachers responded favorably to NatureScope, however, the materials were criticized as too simple for seventh grade. The NatureScope evaluation portion of the study indicates that the materials may be best suited for fifth grade students of average ability. / Ph. D.