Research methods and study limitations
The ISSPP utilized a multi-case study methodology that employed purposive sampling in selecting schools in each country. Study sites were selected using, whenever possible, evidence o student achievement that exceeded expectations on standardized tests, principals’ exemplary reputations, and other indicators of site-specific success. In other words, ‘successful’ principals were selected based on a range of evidence indicating that their schools had been successful under their leadership. Thus, the project rests upon an a priori and mainly circumstantial argument that if school improvement (however measured) had occurred during a principals’ term, s/he may have had some hand in making it possible. Our primary objectives were to determine, in each case, whether key participants – teachers, support staff, parents, students and the principals themselves – believed the principal had played a key role in a school’s success and, if so, what was it about principal traits, attitudes, beliefs, behavior which had made it happen. For example, in New York, where the US sampling was done, seven schools were selected, each having shown evidence of improved student performance on standardized tests during the tenure of the principal studied.
Primary data were then gathered from interviews with each school’s principal, teachers, support staff, parents and students employing a common, semi-structured interview protocol developed specifically for the ISSPP and used in every case. Essentially, the interview protocols were derived from the four research projects described in the theoretical framework, focusing particularly on the four core leadership practices identified by Leithwood and Riehl (2005): 1) setting directions; 2) developing people; 3) redesigning the organization; and 4) managing the instructional program. About 20% of teachers were randomly selected for interviews, but parents and students were largely selected on a volunteer basis. For the purpose of triangulation, secondary data were also obtained from official school documents, minutes of meetings, press reports, historical sources and ethnographic notes made during visits by the research teams. Interviews were fully or partially transcribed, coded and then analyzed specifically in relation to the key questions noted above and more generally in terms of the theoretical framework.
To date, the ISSPP has produced over 100 cases, more than 70 publications in refereed journals, including 3 books. It now consists of 14 countries:
It is the largest corpus of international studies of successful school leadership ever undertaken. It has become the largest and most long running research network on successful school principals.