Problems with the Assessment of Performance in Practical Science: Which way now?

This paper presents an overview of the problems associated with the assessment of practical work in science. We identify two theoretical positions from which different emphases for teaching and assessment flow and examine some of the available evidence on possible methods of assessment which articulate with these two positions. We consider the position adopted by the UK National Curriculum in science and its response to the problem of reliability. We explore possible ways forward which maintain the integrity of investigative work within the curriculum. Finally, the notion that there might be a separate ability, namely an ability to do practical work, is addressed and its consequences considered.