Analysing assessment practice: how useful is the summative/formative divide as a tool?

A view of assessment as 'naturally' divided into the categories of formative and summative has become a taken-for-granted way of thinking about, talking about and organising assessment in universities, at least in the UK where the division is inscribed in national, institutional and departmental policy and guidance (eg. Quality Assurance Agency, http://www.qaa.ac.uk). In these documents summative and formative assessment tend to be understood as serving separate purposes with summative assessment understood as summing up the level of performance and formative assessment as feeding into future learning.
We question the utility of the division in terms of better understanding assessment practices on the basis of an empirical study undertaken in a higher education institution in the UK. The aim of the Assessment Environments & Cultures project is to gain a better understanding of how academics assess and why they assess in the ways that they do. Interview and observational data have been collected from academics working in three subject areas: Design, Business and Applied Sciences. Initial analysis has focussed on the discourses in use and the subject positions taken up by academics when they talk about and undertake assessment.
Analysis of our data suggests that, whilst academics used the categories of formative and summative to talk about their assessment practices, the distinction between assessment purposes may be 'messier' than the separate categories imply. Various examples from the project will be introduced to illustrate this point. This raises a number of questions in terms of researching assessment practices that will be raised for discussion at the roundtable. For example:Might it be useful to understand formative and summative assessment as occupying a shared and contested space rather than as distinct categories?