摘要：Teacher change is a major variable in school change. Such a change depends on external and contextual factors (aspects of the teaching position, labor conditions, administrative and organizational conditions, etc.) as well as on internal factors related to professional knowledge. In addition, both kind of factors are interdependent and mutually influencing and reinforcing. That is, there will be no generalized change among teachers until their labor conditions are changed, however, this change alone will not guarantee an innovative evolution in their professional practices. Having this in mind, our reserach program has the main of goal the construction of a more rigorous knowledge on teachers' professional knowledge and teacher preparation models that facilitate its evolution.
关键词：science teacher preparation ; professional knowledge ; constructivist context
