Mayer, GesaGesaMayerEllinger, DorotheaDorotheaEllingerSimon, SiskaSiskaSimon2023-03-152023-03-152022The Emerald Handbook of Challenge Based Learning, Emerald Publishing Limited, Bingley: 325-344 (2022)http://hdl.handle.net/11420/15003In this chapter, we present our findings and ideas regarding the involvement of external partners in challenge-based learning (CBL). In particular, we address two questions: Firstly, whether it is inevitably necessary and/or worthwhile to work with external partners. Secondly, in case external partners are to be included in CBL, what needs to be considered in order to make the cooperation rewarding for teachers and students. Therefore, we identify different roles external partners may assume as well as benefits and problems that can arise from this in terms of the implementation and learning process. Our insights are based on qualitative expert interviews with five teachers and three students from courses with and without external partners at the Hamburg University of Technology (a subsample of our larger quantitative and qualitative study on CBL implementation within the ECIU), our own experience in teaching CBL, as well as on literature reviews. Our findings suggest that roles and functions of external partners are various: They may come into play as a training partner, as a challenge provider, as an expert in the field and/or as a feedback provider. They may take over several roles at the same time or just one out of it; they may be defined as part of the team of learners or join in at special occasions only. While there are certain advantages unique to having external partners, some roles may also be covered without (permanently) involving externals. In any case, working with externals requires continuous communication and negotiation regarding role expectations, positions, and activities throughout the process. To facilitate this, the chapter introduces a model to systematically analyze and balance interactions with external partners.enBook Part10.1108/978-1-80117-490-920221014Other