The Stages of Concern (SoC) Questionnaire was developed in order to measure the attitudes of individuals toward innovation. The Concerns Based Adoption Model provided the theoretical basis for the instrument. According to this model, individuals are first concerned with themselves, later with the details of the task, and finally with the impact of their own efforts. Recent longitudinal studies have demonstrated the validity of the SoC Questionnaire; two such studies are described in this report. In one study, urban elementary school teachers attending a workshop completed the SoC Questionnaire which measured their concerns about a new diagnostic reading program. In the other study, the Southwest Educational Development Lab used a prototype SoC Questionnaire to measure concerns about their preschool Thinking and Reasoning program. In both studies, the SoC Questionnaire indicated that persons having little experience with innovation had more awareness, informational and personal concerns than persons with greater experience. Those with greater exposure to innovation had more advanced levels of concerns about collaboration in use of the innovation, and about refocusing, or considering more effective alternatives. (MV)