Existing qualitative studies of school principals suffer from procedural or conceptual shortcomings that result in failure to clarify the principal's instructional role. This paper describes the methodology and procedures of a year-long, multimethod, multilevel field study of 12 school principals. First, the background for the study (the literature review, preliminary interviews, and selection of participants) is summarized. Then each of the various research activities employed in the study is described. Phase I procedures include school description instrument and initial interview, the shadow and reflective interview, the organizational cruise, and the site visit. Phase II procedures involved classroom observations and reflective interviews, structured interviews with teachers, student interviews, and use of the Instructional Organization Instrument to provide baseline data about classroom and school operations. Data samples are provided, and data management and analysis procedures are discussed. Finally, the advantages and disadvantages of presenting findings involving lengthy case studies are discussed. Included are tables, 4 appendices containing interview protocols and the Instructional Organization Instrument. Contains 52 references. (MLH)