This paper discusses the development and theoretical premises of the Expert Science Teaching Evaluation Model (ESTEEM) as well as research into this model from 1990 through 1993. ESTEEM was developed under the aegis of the Center for Research on Educational Accountability and Teacher Evaluation (CREATE) with major goals of defining expert science teaching, developing instruments to assess it, and developing an expert teaching model. Both qualitative and quantitative analyses have been done to develop and validate the first instruments and have involved nearly 200 fourth- through eighth-grade teachers. The studies have indicated that expert teachers are defined by the evaluation criteria and that there is only about a 50% agreement in the top quartile of teachers sorted by two developed measures, the Classroom Observation Rubric and the Student Outcome Assessment Rubric, suggesting caution in considering what expert means. The theoretical base derives from the constructivist movement, Scriven's Duty Based Evaluation, and the novice through expert literature. Research so far suggests that most science teaching is done from a teacher-centered approach, disseminating content at the lower end of the higher order thinking skills continuum. Two figures and 14 tables present some research findings. (Contains 73 references.) (SLD)