Research about the benefits of formative assessment as a means of improving student learning has encouraged policy-makers and teachers in countries like the UK, Australia and New Zealand to promote and use classroom-based assessment for learning in the qualifications arena. However, recent research suggests teachers are implementing a narrow interpretation of formative assessment in classrooms using techniques that focus on assessment procedures and practices to assure students comply with criteria and achieve awards for external qualifications. This variation on 'teaching to the test' has led to the coining of the phrase 'assessment as learning' to indicate the instrumentalism that results from such restricted practice. This paper reports on findings from case studies of two schools in New Zealand where secondary school students are learning how to perform science investigations under direction, for a curriculum standard that is a component of a national standards-based qualification. The findings reveal that students' assessment and learning experiences reflect the emerging international trend of 'assessment as learning', but strategies for redressing some of the undesirable aspects of this limiting form of formative assessment in this New Zealand context are identified.