"Ah! he wants to win!": Social responses to playing Tic-Tac-Toe against a physical drawing robot Avital Dell’Ariccia Technion Israel Institute of Technology Haifa, Israel Alexandra Bremers Cornell Tech New York, NY, USA Wen-Ying Lee Cornell University Ithaca, NY, USA Wendy Ju Cornell Tech New York, NY, USA ABSTRACT We present an exploratory human participant study (N=3) examin- ing how people interact with a pen-plotting robot that interactively plays Tic-Tac-Toe on a shared physical sheet of paper. Each par- ticipant played a round of Tic-Tac-Toe against the robot, while we observed. We particularly focused our observations on the par- ticipants’ physical and social behaviors during game interaction, as well as in-moment reactions from the participants. Following each game, we performed semi-structured qualitative interviews to understand the user’s experience interacting with the robot. Our questions were designed to elicit comparisons of their experience with less tangible interactions that players might have with a com- puter or phone-based app, as well as more traditional interactions that players might have with other people. We found that partici- pants directly addressed the robot by talking to it during play and openly expressed competitiveness against the robot. Furthermore, participants displayed careful movements around the robot and attentively observed its behaviors. Based on these initial insights from our exploratory study, we are planning future experiments to investigate the efect that the mutuality of the physical Tic-Tac-Toe interaction has on social responses to the robot to understand what this implies for embodied and tangible interaction design. CCS CONCEPTS · Human-centered computing → Empirical studies in inter- action design;· Hardware → Tactile and hand-based interfaces. KEYWORDS pen plotter, drawing game, paper interface, human-robot interac- tion, computer vision ACM Reference Format: Avital Dell’Ariccia, Alexandra Bremers, Wen-Ying Lee, and Wendy Ju. 2022. "Ah! he wants to win!": Social responses to playing Tic-Tac-Toe against a physical drawing robot. In Sixteenth International Conference on Tangible, Embedded, and Embodied Interaction (TEI ’22), February 13–16, 2022, Daejeon, Republic of Korea. ACM, New York, NY, USA, 6 pages. https://doi.org/10. 1145/3490149.3505571 Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for proft or commercial advantage and that copies bear this notice and the full citation on the frst page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s). TEI ’22, February 13–16, 2022, Daejeon, Republic of Korea © 2022 Copyright held by the owner/author(s). ACM ISBN 978-1-4503-9147-4/22/02. https://doi.org/10.1145/3490149.3505571 1 INTRODUCTION Tic-Tac-Toe is usually played with friends and family as a way to pass time together. The game is short, and inconsequential. It is easy to initiate a game spontaneously, since nothing more than a pen and a scrap of paper is required. Even though it is a compet- itive game, there are also elements of sociability to the practice: cooperation is required for turn-taking, there are feelings of mu- tuality that come from marking the same shared paper, the board design is symmetrical, so that anyone looking at the board from any perspective would have the same sense of the game state. It is enjoyable enough that people often play several rounds of the game, even though the strategy is not very deep or complex. We believe that some part of the social enjoyment of playing Tic- Tac-Toe comes from the physical co-presence and shared physical action with the žopponentž, and that such feelings would be present even if we were not playing against another human player [11]. This intuition speaks to the broader question of the benefts of physical robots and tangible interfaces in general. To understand these issues better, we built a Tic-Tac-Toe playing plotter. Our system uses a camera and computer vision to detect where someone has played on the board, and has the user press a drawn łbuttonž to signal the end of their turn. The system phys- ically places a mark on paper by holding and moving a pen. We used this platform in an exploratory study with three participants (N=3). We describe our observations from these games, and re- port responses from the semi-structured interviews that followed the human-robot interaction. The fndings from this system and study indicate that the mutuality of physically co-present robots and tangible interaction evokes social responses despite the lack of anthropomorphic form of the pen-plotter robot. 2 BACKGROUND 2.1 Tic-Tac-Toe with robots Playing Tic-Tac-Toe is widely used as a dummy task for devel- oping robotic systems, because of its simplicity, universality, and association with fundamental aspects of engineering. For exam- ple, Vuittonet and Gray looked into Tic-Tac-LEGO to investigate coordinated robotic control [21]. Advanced kinematic models and interaction mechanisms have also been developed and tested un- der the scenarios of playing Tic-Tac-Toe with the Nao humanoid robot [4, 12, 18]. Less research has taken advantage of this simple game to study interaction, despite the game touching on essential