While assessment and its effects on learning such as 'washback' have been the subject of much debate (e.g. Alderson & Wall, 1993; Bachman, 1995: 356; Alderson & Hamp Lyons, 1996; Shohamy et al, 1996; Andrews et al, 2002), assessment as a tool for developmental, not merely evaluative, purposes has probably not received sufficient attention (e.g. Dickinson, 1996: 101; Gardner, 1999). Of interest to this study is a project by Dickinson (1996: 106) in which participants (tutors and learners) are shown to have benefited from a scheme of collaborative assessment.[Copyright of Language Learning Journal is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/09571730585200161]