Discussion of different types of methodological approaches, and description of the research methods used to study an innovative secondary school in England, make clear why the case study was chosen as the method to employ. The methodological approaches considered included the positivist or scientific method, involving external observation and the testing of hypotheses; the interpretative approach, studying sociological phenomena from within; and grounded theory, stressing the derivation of theory from data. The choice of the case-study method allowed the combination of elements from all three approaches. In the research itself, a "low-profile" participant-observer technique was used. The research on the school went through three phases, each with a differing set of theoretical orientations and data collection methods. In phase 1, involving his introduction into the school, the researcher took an open, aproblematic approach and used interviews and document analysis. In the second phase a theory was developed from the data, while data collection emphasized observation and some interviewing. Phase 3 saw order emerge as the theory was developed; information-gathering methods included observation, interviews, questionnaires, and document analysis. Charts in the appendix illustrate the phases of the research. (RW)