It is a great pleasure to present the proceedings of the ninth ACM Symposium on Spatial User Interaction (ACM SUI 2021), held virtually November 9-10, 2021. From its inception, the Symposium has focused on interactions spanning across multiple dimensions, breaking the constraints of conventional two-dimensional interfaces and transcending into the three-dimensional space that surrounds us. SUI has encompassed all aspects connected to this fascinating area: from touch to gaze, from sitting at a desk to movement, from augmenting our reality to replacing it with artificial ones, and beyond. We now live in an age where the technologies that support these activities are widely available, affordable, and competing with each other to improve the user experience even further. This present seemed like a distant future not so many years ago. In this rapidly evolving environment, we are expanding the boundaries of our knowledge of how the spatial dimension can be leveraged to empower users to achieve more. But we are also discovering new challenges and new limitations to overcome. We must be ready to meet them and make sure that these insights can reach the widest audience.
This year, the Symposium was held in the middle of the COVID-19 pandemic, which impacted many researchers in the way we perform, research, and travel. While COVID-19 has been with us for a while, there is still no clear indication when we will return to pre-COVID times or if we are faced with a new normal. While it is true that vaccinations have improved in-person studies, multiple challenges persist and new approaches have required researchers to find alternative ways for the evaluation and validation of spatial interaction approaches. This challenge will provide an opportunity for all of us to think about our future evaluations.
SUI 2021 received 43 submissions including 33 long papers and 10 short papers. These submissions come from numerous countries including Austria, Canada, China, Colombia, France, Germany, Hong Kong, India, Japan, New Zealand, Slovenia, Switzerland, Taiwan, United Kingdom, United States, making SUI a truly international conference. Reviews were conducted by an international team of experts in their respective areas of spatial user interaction. Three submissions were identified by program committee members as quick rejects because they used the wrong format or were not anonymized in line with the double-blind review process at SUI. All other submissions received at least two reviews by program committee members and an additional external review by experts recruited by the program committee. With the double-blind review process at SUI, only the program chairs and primary reviewers were aware of the identity of authors of submissions they reviewed. After these reviews were completed, an online discussion phase ensued in which the reviewers for each paper came to a consensus initial recommendation for that submission. The program chairs then discussed the papers by email and convened for a video-chat-based meeting, where the decisions were made for each paper. Those program chairs with conflicts of interest recused themselves from the decision-making process of the corresponding paper submissions. This meeting resulted in 2 long papers being accepted as well as 14 long papers and 1 short paper being conditionally accepted. Following their conditional acceptance, each paper then went through a minor revision cycle and was assessed a second time by its primary reviewer and/or a program chair to check whether the final version satisfactorily addressed reviewer concerns. The review process yielded 17 accepted papers (16/33 full papers, and 1/10 short papers), for an overall acceptance rate of 39.5%. Eight papers were conditionally accepted as posters. Similar to the process for papers, each conditionally accepted poster was revised and then assessed a second time by its primary reviewer and/or a program chair. This action by the program chairs allowed a quicker turnaround for posters.
For the posters and demos, we received 6 poster submissions and 1 demo submission. The Posters, Demos, and Interaction Chairs assigned the submissions among themselves avoiding any conflict of interests after an initial format-check process and reviewed the assigned submissions individually. After this review period, the Chairs had multiple discussion meetings to reach a consensus agreement on the final accepted posters and demos, while cross-checking each other’s thoughts and reviews. The process yielded 4 accepted posters and 1 accepted demo paper, in addition to the 8 papers turned into posters which provided a grand total of 12 posters for this year’s SUI. We believe that the low submission rate of posters is due to the lack of face-to-face opportunities to present them and some people seeing less value in a virtual poster presentation. As a community, we need to continue to improve hybrid modalities where people feel that either virtual or face-to-face presentations provide a good avenue to network and share their research.
Many individuals contributed a great deal of time and energy towards the success of the Symposium. We would like to thank the 171 paper authors and the 26 poster/demo authors for sending their work for consideration to SUI 2021, as well as the 18 members of the international program committee and the 45 external reviewers for their many hours of dedicated efforts to select the papers that appear here. We would also like to acknowledge James Stewart for his reliable assistance with the precision conference system (PCS) reviewing system and Stephen Spencer for assistance with the ACM Publishing Pipeline (TAPS). We warmly thank the SUI Steering Committee for their valuable advice and leadership. We thank the ACM Special Interest Groups on Graphics and Human-Computer Interaction (SIGGRAPH, SIGCHI).
We hope that our vision for the program and for the Symposium will be of interest and that this coming together of researchers and practitioners will not just be the destination of a year-long adventure, but the stepping stone towards new ideas and successes.
ACM SUI 2021 General Chairs
Francisco R. Ortega, Colorado State University, United States
Robert J. Teather, Carleton University, Canadas
ACM SUI 2021 Program Chairs
Gerd Bruder, University of Central Florida, United States
Thammathip Piumsomboon, University of Canterbury, New Zealand
Benjamin Weyers, University of Trier, Germany
ACM SUI 2021 Posters, Demos, and Interaction Chairs
Anil Ufuk Batmaz, Kadir Has University, Turkey
Kyle Johnsen, University of Georgia, United States
Christoph Borst, University of Louisiana at Lafayette, United States