This paper reports on a two-year classroom investigation of primary school (Years 1-8) technology education. The first year of the project explored emerging classroom practices in technology. In the second year intervention strategies were developed to enhance teaching, learning and assessment practices. Findings from the first year revealed that assessment was often seen in terms of social and managerial aspects, such as teamwork, turn taking and co-operative skills, rather than procedural and conceptual technological aspects. Existing formative interactions with students distorted the learning away from the procedural and conceptual aspects of the subject. The second year explored the development of teachers' technological knowledge in order to enhance formative assessment practices in technology, to inform classroom practice in technology, and to enhance student learning. Intervention strategies were designed to enhance the development of procedural, conceptual, societal and technical aspects of technology for teachers and students. The results from this intervention were very positive. This paper highlights the importance of developing teacher expertise pertaining to broad concepts of technology, detailed concepts in different technological areas and general pedagogical knowledge. The findings from this research therefore have implications for thinking about teaching, learning and assessment in technology.