The Eco-Behavioral System for the Complex Assessment of Preschool Environments (ESCAPE) has been developed for the evaluation of preschool environments by way of the interactions of students with such aspects of the classroom ecology as activities, materials, and grouping configurations, as well as teacher behaviors. The system follows a momentary time-sampling approach and tracks individual children across all activities in a typical preschool day allowing for the recording of 12 categories of these variables. The ESCAPE system allows coding for (1) the variety of adults who interact with the child, (2) teacher behaviors directed specifically to a target child, and (3) simultaneous occurrences of three different categories of student behavior. Data can be summarized to represent the percentages of time the target child spends engaged in each coded variable or unconditional probabilities to indicate the probability of various student behaviors given a specific arrangement of ecological variables. Pilot data on 12 children illustrate the system's potential application with process-product program evaluation. Implications of expanding the focus of process assessment beyond student behavior to include ecological and teacher behavior variables within early intervention program evaluation research are discussed. (Author/DB)