Beliefs about the validity and merit of self-, peer- and group-assessment practices are presented from 213 pre-service primary teachers and 30 staff who teach them. Both groups were surveyed using comparable items. A subset of seven staff participated in semi-structured interviews. Staff were far more supportive of peer- and self-assessment practices than their students with both groups indicating modest support for group assignments. While pedagogical factors best represent the staff support for engaging students in assessment of their own and their peers' work, several staff in interviews revealed that their high level of support for peer-assessment was closely linked to a time-saving factor. Peer-assessment was more often used than self-assessment while both practices were reported to have increased over the past two to three years. These findings are consistent with the reported increase in participative assessment practices in higher education generally. An important implication of this research is that in order to optimise the use of participative assessment, staff need to better prepare their students by modelling and communicating their reasons for adopting such practices. (Contains 4 tables.)