Successful integration of technology is a key goal of recent large investments in technology infrastructure in Western education systems. Conditions affecting successful Information Communications Technologies (ICTs) integration in the classroom are in need of future elucidation. / An extensive study was conceived to investigate types of ICT integration, teachers attitudes regarding ICTs, modes of professional development and teachers perceptions of formal and informal leaders. A 152 item questionnaire was developed and used to gather data from a School District in Nova Scotia, Canada where 750 out of a potential 996 grade three to twelve teachers and administrators responded. Statistical analysis from this school district was then used to guide the researcher to focus upon two elementary, two senior, and one junior high school. At these schools 71 teachers and administrators were interviewed and/or observed. / Further statistical analysis was then conducted to draw out commonalities and differences among and between categories based on school type, grade, subject taught, age and position of employment. Both quantitative and qualitative findings worked together during this analysis. / From the above analysis, structural equation models were employed to confirm findings and show how teacher attitude, professional development and leadership may interact with each other as well as how they may affect levels of classroom ICT integration. / The data show evidence of complex relationships between the components of teacher attitudes, professional development and leadership, and the level of technology integration in the classroom. The measures of student-centredness, student-collaboration as well as levels of cognitive engagement all demonstrate significant relationships to the level of technology integration occurring in the classroom. As well, teacher collaboration and particular modes of professional development may yield higher levels of technology integration. Particular leadership characteristics may result in classroom ICT integration occurrences which may further be affected by other categories of school level, grade, subject taught, age and position held. It was found that models addressing teacher attitude, professional development, leadership and ICT integration may work at that holistic level. However, when moving from these general to more specific contexts, these models fail. Through further analysis, other statistical models, supported by qualitative data, demonstrate statistical viability at levels lower than district-wide. / It was also found that an on-going needs-based professional development model may be needed to form the superstructure that could support differentiated professional development experiences. The needs of individuals and groups of teachers could be assessed in order to accommodate their preferred professional development modes and content requirements. / Thesis (PhDEducation)--University of South Australia, 2006.