To be credible, a curriculum that aims to achieve a critical scientific and technological literacy must be based on a model of curriculum development that seeks to encourage and support teachers in becoming critically literate about their own educational practice (Pedretti and Hodson, 1995: 468).
It is our (authors') contention that effective STS curriculum development requires that groupd of teacher who know the students, the locality and the school environment well, are brought together to work on theoretical and practical issues related to the design and implementation of learning experiences in a critical and supportive environment (Pedretti and Hodson, 1995: 468).
Stenhouse's (1975) famous remark that there can be no curriculum development without teacher development. Like Stenhouse, we (authors) see curriculum not as something which teachers have to be trained to implement, but as a resource to help teachers critique and reconstruct their professional practices (Pedretti and Hodson, 1995: 473).
Strongly held views that teachers should play a central role in STS policy, planning, and curriculum development were evident in many comments throughout the lifetime of the project (Pedretti and Hodson, 1995: 475).
The frequent and sometimes spectacular failures of top-down curriculum development can be laid at the door of the basic assumption about the relationship between developer and teacher: that teacher simply receive and then act upon the curriculum wisdom transmitted by developers. This approach ignores that teachers are people who bring to the curriculum their own ideas, experiences, perceptions, and values. Teachers possess a range of curriculum knowledge, skills, and attitudes ranging from theory-based principles of procedure, through professionally acquired experience-based knowledge, to taken-for-granted common sense knowledge and what we (authors) might call "teacher folklore". This cluster of tacit knowledge, beliefs, and values has been variously termed "personal professional knowledge", "pedagogical knowledge", "practical curriculum knowledge", and so on (Carter, 1990; Johnston, 1992 cited by Pedretti and Hodson, 1995: 476).