"Collaboration with fellow students rather than working in isolation can help to maintain student motivation and improve the quality of their learning as it opens up the possibilities for discussion, new ideas and varying approaches."
McDowell, L. and Sambell K. (1999) The experience of innovative assessment: student perspectives, in Brown, S. and Glasner A (eds) "Assessment Matters in Higher Education", Open University Press.
Working in groups can reinforce and consolidate students' learning, whilst also helping to develop important employability skills. It is not without its challenges though. Students will often complain about unfair distribution of work across the group, due to some students 'freeloading', and this can be especially difficult if, where the work is assessed, students only receive a group mark, with no account taken of individual effort and achievement.
To offset these difficulties, journal entries, portfolios, learning logs or critical incident records can be used in tandem with groupwork assessments. These assess an individual student's capacity to reflect on their contribution to the task, rather than the outcome of the task itself being assessed. Alternatively, a proportion of the marks can be devoted to peer assessment, with group members anonymously rating each others' input, and an average individual mark being arrived at. The marks from these activities then form an additional component of the assessment for the module.
Explicit allocation or negotiation of team roles by the tutor, or between the group, in advance of the task, can also help to offset the risk of 'free riders'.