Educational policies and curriculum documents largely emphasise the idea that assessment should be "diverse": that teachers should use versatile assessment practices such as tests, self- and peer-assessment and portfolios instead of mainly drawing on uniform practices, such as examinations. In this study, we examined the diversity of assessment in the low-stakes assessment culture of Finland where the national curriculum emphasises the ethos of Assessment for Learning. We were interested in how the diversity of assessment (or the lack of thereof) is related to student perceptions of assessment. We utilised both multilevel and person-oriented methods in our analysis of a national evaluation dataset of 187 Finnish primary and lower secondary teachers and their 2370 students. First, we noted that according to the teachers' responses, classroom assessment in Finland is not particularly diverse. At the same time, students did not find assessment particularly helpful for their learning. Second, a multilevel analysis revealed varying correlations between the prevalence of various assessment practices and students' perceived usefulness of the corresponding practices. Third, we explored teacher subgroups in terms of their 'assessment menu' through a latent class analysis. All identified teacher subgroups drew heavily on closed-book examinations. Finally, we analysed whether the assessment perceptions of students differ according to their teacher's latent class. The students whose teachers used the most diverse assessment menu reported the most pressure in assessment. We suggest these findings stem from the socio-historical context of pedagogical conservatism in Finland, combined with the low stakes of assessment. We discuss the importance of widening teachers' assessment practices in order to promote sustainable student perceptions of assessment, yet such assessment diversity must be valued in the educational system, and it needs to be based on sound pedagogical design.