Presented is the fourth in a series of formative evaluation reports on "Me and My Environment", a 3-year environmental sciences program for 13- to 16-year-old educable mentally handicapped (EMH) children. The rationale and standards for monitoring instructional effectiveness are explained, and student performance is reported on field tests of items assessing instruction in Units 1 ("Exploring My Environment"), 2 ("Me as a Habitat"), and 3 ("Energy Relationships in My Environment"). Described is a small-scale field test in which techniques of observing, describing, comparing and ordering objects were taught to 14 EMH students through the use of stereograms and viewers. Discussed are the implications for curriculum development of a survey of 235 EMH adolescents concerning their attitudes toward and use of tobacco, alcohol, and unprescribed drugs. Four abstracts of studies on the functional abilities of EMH students are provided, and comments are offered relating findings about cognitive abilities and students' manipulative skills to curriculum development. (LH)