Group work benefits student learning in many ways, but group work assessment may be challenging for academics and sometimes is perceived as less fair than individually set assessment tasks. Peer assessment (PA) and self assessment (SA) represents a possible approach supporting lecturers and students to better differentiate individual contributions to group-based assignments. In this study, we explore the students' perception of SA and PA as strategies to facilitate the assessment of the process of group work and to contribute to increasing the sense of fairness in assessment. With these aims, we designed a study of an assessment practice in which students were involved as partners in the assessment and grading process of a group project assignment. At the end of the course, and when the SA and PA experience concluded, we administered a survey. The findings show that (1) including SA and PA strategies in student tasks enhances the students' perceived sense of fairness in the assessment process, (2) the specifics of the instructional design do not have a significant effect on student perceptions of this form of assessment, and (3) sociodemographic factors such as the academic year, the degree major and the age of the students have a moderate effect. We conclude that SA and PA improve the sense of democracy of the assessment process, as this is not only in the teachers' hands but also shared and agreed upon within the group.