The Stages of Concern Questionnaire (SoC) was developed to assess the seven hypothesized Stages of Concern About the Innovation. These stages of concern are a primary dimension of the Concerns Based Adoption Model developed at the Texas Research and Development Center to conceptualize and facilitate educational change. This manual describing the development of the measure has been designed to serve the needs of researchers, facilitators of change, and users of the SoC questionnaire. Both psychometric and interpretative information are included. The stages of concern are defined, the questionnaire is described, reliability and validity data are presented, and administration and scoring directions are given. The complete SoC questionnaire and sample data for computer processing are appended. (Author/MV)