The first in a series of papers details the methodology of a study on the environmental setting of the learning disabled (LD) adolescent with attention given to interventions applied on behalf of the LD adolescent, conditions under which he/she operates, and support systems available to the student. Sections address the procedures for selecting the LD, low achieving (LA), and normal achieving students in grades 7 through 12 who served as Ss; research setting and design; measurement components including learner characteristics and environmental variables, testing instruments, and other assessment instruments; procedures for tester training, students participating, and school record searches; and methods of data analysis. Tables with statistical data and definitions of exclusionary conditions are offered; and school records sheets, instructions for validation team members, and sample questionnaires are appended. (SB)