How can teachers be helped, at relatively little expense, to improve their professional practice? This problem was addressed in "Improving Formative Assessment in Vocational Education and Adult Literacy, Language and Numeracy Programmes"--the IFA project. Adopting a specific problem-based methodology as part of an action research approach, the IFA project involved 49 teachers in three structured one-day workshops within a time frame of 6-12 months. Attendance at the workshops was funded; but between workshops, without further support, teachers developed formative assessment strategies and practices in their own teaching time with students. The IFA workshops were led by experienced researchers using a common set of guidelines across 10 project institutions (a comprehensive school, further education colleges, and various adult education sites). In this article the authors evaluate the extent to which this relatively low-cost action research approach was effective and reflect on its wider potential. (Contains 4 tables and 2 notes.)