This study examines teachers' perceptions and comprehension of their school community support for change in implementing a new teaching approach in science and technology in the context of a reform initiative at the secondary level. It is part of a two-year research-intervention conducted with science teachers from a private school. Data was first collected through ethnographic notes and audio-recorded focus groups with 256 students. Although appreciated by students, the implementation provoked conflicts at the school community level. Building on the Cultural-Historical Activity Theory (CHAT) and on the expansive learning cycle aiming at transforming an activity system, the actual study aims at deepening our understanding of the origins of contradictions at and between some of the poles of multileveled activity system that is object-oriented, mediated by artefacts (instruments), and comprises the community, rules and division of labor poles. Findings highlight the clash in the participant teachers' values versus the community's in implementing innovative teaching practice. Teachers report favoring nontraditional ways of teaching and giving more room to adolescents' autonomy while the stakeholders (school principal, parents) are often looking for traditional teaching practices and students' school achievement. The results put into evidence the need to identify common grounds and to make sense of the new science teaching approach aiming at promoting students' autonomy, critical judgment, and school success levels.