## 7 Conclusions and Future Work  
The gradual incorporation of technologies in educational environments can support teachers in developing highly valued competencies in the work environment [49]. Under this perspective, the measurement of aspects associated with non-verbal communication becomes relevant since it allows us to understand how subjects interact in collaborative activity, as well as providing effective feedback to both students and teachers.  
This paper presents the design and development of a MMLA platform using sensors to capture and visualize audio and video data. It graphically provides feedback analytics to support collaboration assessment in face-to-face environments (co-located collaboration). For this purpose, we integrated hardware and software, and incorporate machine learning techniques to develop a scalable system. The platform allows to detect the amount and duration of the team members' spoken interactions, body postures, and gestures. These features are presented in five different visualizations to provide insights about theoretical collaboration constructs.  
We conducted a case study to compare the visualizations provided by the system in two different situations: collaborative and competitive activities. The results suggest that the provided visualizations help to identify issues on cognitive contribution, assimilation, self-regulation, and integration of the team members. They could also support teachers to decide whether they must assist a team in fostering collaboration.  
While the results are naturally constrained to the characteristics of the activities in which we tested the platform, they provide initial evidence about the technical feasibility of extracting behavioral indicators and traces using MMLA to give insights on team collaboration.  
Future work will focus on the improvement of the platform's scalability in order to allow real-time monitoring of various teams. Moreover, future work will cover the extraction of features from verbal communication, allowing the identification of the topics/subjects of the team members' spoken interactions and better supporting different collaboration constructs in more extended and complex activities. Once real-time monitoring is implemented we intend to assess to what extent teachers' actions based on visualizations input affect students participation in the activities and helped to enhance their collaboration. For that, we intend to follow some conditions and guidelines for fruitful collaboration identified by [50].  
Conceptualization, R.M., R.N., D.M. and F.R.; methodology, R.M. and R.N.; software, D.M.; C.C. and T.T.T.P conducted related works section; focus group, R.N., D.M., C.C., T.T.P. and R.M.; formal analysis, R.N., D.M., C.C., F.R. and R.M.; resources, R.M. The final manuscript was written and approved by all authors. All authors have read and agreed to the published version of the manuscript. This research was funded by grant ANID/FONDECYT/REGULAR/1211905. The study was conducted according to the guidelines of the Declaration of Helsinki, and the protocol was approved by the Institutional Ethics Committee of Universidad de Valparaiso (protocol code CEC-UV 236-21). Informed Consent Statement: Informed consent was obtained from all subjects involved in the study. The data presented in this study are available from the corresponding author upon request. The authors declare no conflict of interest.