In times of constant change and ever new technologies, lifelong learning is becoming increasingly important. Massive Open Online Courses or MOOCs are an excellent tool to reach large parts of the population in a short time and with comparatively little effort.

With its own openHPI platform and the openSAP, OpenWHO, and mooc.house platforms operated for various partners, HPI makes an important contribution to digital enlightenment both in German­ speaking countries and internationally. In many areas, the platform is state of the art and at least on a par with the internationally more well-known platforms. Especially in the development and application of new teaching and learning methods and their technical support, openHPI is also internationally trend­ setting.

This dissertation deals with the possibilities of technical and didactic support of assessable team tasks in the context of MOOCs. Because of the size of the courses-usually a small teaching team is facing several thousand participants-a manual assessment of the participants' work by the teachers is not possible. Here, one of the alternative possibilities for the evaluation of tasks, the so-called peer assessment, is used and adapted for the special conditions of team assignments. Over the past five years, an iterative long-term study has been carried out, using different qualitative and quantitative methods of evaluation.

The result of this research is a deep insight into the mechanisms of teamwork in scalable digital learning platforms, as well as a set of recommendations for improving the collaborative features of the HPI platforms, some of which have already been implemented or currently are being implemented.