This thesis investigates the views of principals in government schools in the Australian Capital Territory (ACT) regarding school based management (SBM). School based management is defined as the delegation of certain decision making functions from central bureaucratic control to a group of personnel located at the school site. In the case of the ACT, delegation of decision making to school sites began in 1974. An additional set of responsibilities was delegated in the 1997/98 period. This study concentrates on the latter period but also takes the extended period of devolution into account. This investigation is based on qualitative and quantitative methods of enquiry and data collection to investigate principals' perceptions of SBM, particularly in relation to the demographic variables of the schools, and selected personal and professional characteristics of the principals. Initially twenty six semi-structured interviews were conducted with principals to determine a framework of seven constructs in relation to SBM. Qualitative data are reported by drawing on the extensive unabridged transcripts of the interviews. The data arising from the interview stage formed the basis for construction of a questionnaire administered to the total population of ninety seven principals in government schools in the ACT. The questionnaire consists of demographic, personal and professional items concerning the school and the principal, items related to the impact of SBM, questions regarding the principals' perceptions of satisfaction with their work, and the importance principals place on selected aspects of their role, particularly following the extension of SBM. Results of the questionnaire are reported using frequency distribution for each of the items in the questionnaire, followed by factor analysis and analysis of variance to test significant differences in the principals' views at the 0.05 or greater level. Results of these analyses show that principals have common perceptions in general about the nature and impact of SBM. Principals' perceptions are however, mediated by a number of independent variables. These are gender of the principal, experience of more than one year's work outside the field of education, the sector of their school, ie primary, high school or college, and the geographic location of the school. Their participation in SBM training programs, bureaucratic support to assist them in implementing SBM, and their expressed need for continued professional development are additional independent variables where statistically significant differences are apparent. Principals in this study view the extension of SBM responsibilities more as an administrative function, than an opportunity to engage in restructuring the school. They see that their role has expanded to place strong emphasis on business management and they consider that they are now working in a market oriented climate where competition for students is a real issue. Hours of work have increased, and maintenance of a balance between work and personal life is a growing concern. Despite this they do not want to return to the former arrangements and continue to express satisfaction with the intrinsic rewards of their profession such as contact with students, colleagues and the community. These results provide important insights into the type of SBM evident in ACT government schools at the time of this study. A number of recommendations for future research and practice are presented related to the findings and linked to the key themes arising in the literature.These suggest ways that SBM can and might be used as a catalyst for development of a new paradigm for education, which will meet the needs of a 'knowledge society' (Drucker, 1995) and engage schools in moving 'beyond the self managing school', (Caldwell and Spinks, 1998).