An ethnographic approach to the evaluation of an Elementary Secondary Education Act Title I mathematics project designed for grades 3 and 5 low-achieving students is described. The research was designed as a series of eight disaggregated single case studies of the implementation of the project with the classroom serving as the unit. The focus of the study was the development of ethnographic procedures for observing and describing the way programs are implemented using resource teachers to help classroom teachers improve instructional services for economically disadvantaged minority students. An ethnographic model for use by school district evaluators in studying program implementation was developed. (Author/RL)