In the StarS project, tasks and items for assessing basic skills in mathematics at the beginning of the first year and (for the purpose of learning development diagnostics) at the beginning of the second year are developed. In addition, professional development modules for data-supported lesson development in the context of basic skills in mathematics in Year 1 are being developed. To support lesson development, an overview of criteria for the assessment of support materials will be created, which, in addition to naming quality criteria, will also provide an overview of the available offers.