## 1 Introduction
### Background  
While online learning in higher education offers a wide range of benefits for both teachers and students, there is a strong rationale for in-person teaching and learning on campus. The rationale for in-person education has been seen especially in enabling direct social interaction, hands-on and collaborative learning as well as sustained motivation through presence and communication in a physical academic environment [3]. The qualitative research study by [4] asked the following question: \"Has COVID-19 killed the campus?\". The results from interviews with faculty and students in multiple countries showed that both higher-education teachers and learners perceive social interaction in the physical space to be the core of the campus experience [5]. The shift from face-to-face to fully online education during the pandemic phase was often perceived as an unpleasant experience, mainly due to the absence of direct social interaction and the resulting physical and social distancing [5]. The literature review by [5] revealed the experience of emergency remote teaching (ERT), which forced the shift to online learning and teaching (OLT) due to the well-known emergency situation, can be gradually and meaningfully integrated with methods of in-person interaction in physical spaces in the post-pandemic times.  
Challenges experienced by teachers and learners during the pandemic spurred many discussions about the future of on-campus education [4,5]. The study by [5] asked the following question: \"Now that campus-based university teachers have experienced the unplanned and forced version of OLT, how can this experience help bridge the gap between online and in-person teaching in the following years?\" The expert interviews elicited some plausible predictions and expectations, such as \"the use of technology will be broadly considered in all programs as a strategic and essential aspect\", \"teachers are organisers of events in which students meet with a purpose\", in a \"technology-rich learning environment, the teacher acts as tutor, organiser of the learning process, curator of the learning resources, motivator and project manager of students' learning\" [5]. Moreover, the interviewed experts emphasised the importance of using active learning methodologies such as problem-solving and game-based learning [5].  
The gradual shift from lectures for large groups of students to collaborative activities in small groups started before the pandemic and has been seen as an important catalyst for the transformation of the role of higher-education teachers. The teacher's role has been transformed from a content provider to a group facilitator, as advocated by educational approaches such as flipped-classroom and collaborative learning in groups [6, 7, 8]. Active, participatory learning in small groups has been shown to be more effective, both in terms of content retention and engagement, while increasing the demand for attention of teachers to the individual needs of students [8]. The role of the teacher as a group facilitator has focused on the encouragement of engagement, discussion, and participation of all the group members [8]. However, the new role of a facilitator has been also challenging, especially for teachers aiming to provide individualised attention and support to large groups of students. Therefore, methods for scaling up small group facilitation have gained importance in academic discussions [8]. The OECD report \"Digital Education Outlook 2021: Pushing the frontiers with AI, blockchain and robots\" identified social robots as one of the three technologies that will transform education systems [9]. The case study presented in this paper shows how social robots can be used to scale up small-group facilitation in the context of in-person teaching and learning.