This article aims to contribute to the development of frameworks for evaluating student voice projects in higher education by offering a critically evaluative account of two student voice projects. Although both projects had been underpinned by the principles of participatory (inclusive) research, one appeared to be more successful than the other in engaging students in a productive or meaningful way. In order to confirm and explain these perceived differences, this paper draws on both student voice and participatory research literature to identify two potentially useful evaluation criteria: reach and fitness for purpose. These criteria are applied to three project factors: aims and assumptions, processes and outcomes to produce an amplitude framework for evaluating student voice in higher education. It is argued that this framework has the potential to enable a rich account of the relative successes and failures of student voice initiatives in higher education.