ITS 2010: Applications November 7-10, 2010, Saarbr ¨ ucken, Germany 109 WaveWindow: Public, Performative Gestural Interaction Mark Perry 1,2 Steve Beckett 2 Kenton O’Hara 2,3 Sriram Subramanian 2 mark.perry@brunel.ac.uk beckett.stephen@gmail.com kenton@gwork.org sriram@cs.bris.ac.uk 1 Brunel University, UK; 2. University of Bristol, UK; 3. Microsoft Research Cambridge, UK ABSTRACT Retail products are often experienced through transparent barriers such as shop windows, vending machines or display cabinets. Such surfaces offer opportunities for digital augmentation to enhance the experience at this point of contact. To explore this domain and its challenges, we have developed and evaluated the WaveWindow. This is an interactive see-through display that allows users to interact with digital content that overlays physical items behind a semi-transparent screen. Navigating and selecting content is achieved by waving and knocking on the display. We performed a user study and the resulting user interactions were recorded and analysed, and a number of design recommendations are made for gestural interaction in public settings and their application in a retail setting. ACM Classification: H5.2 [Information interfaces and presentation]: User Interfaces. Graphical user interfaces. Keywords: Performance, gesture, public displays. INTRODUCTION See-through displays that offer the possibility of locating physical objects behind a transparent display are useful in retail, library and museum settings to protect delicate or valuable objects while allowing their inspection. In the case of shopping windows or vending machines where there may be some transaction required to gain access to the physical object they also offer a means of finding out more about the item prior to purchase. Retailers have already developed simple systems to support this activity. For e.g., Polo Ralph Lauren unveiled an interactive shopping window (engadget , Aug. 10, 2006), in which shoppers could view clothing and make purchases via an interactive touch screen, demonstrating retailers’ interest in, as well as the practical feasibility of such see-through displays. To date, most research on use of see-through displays has been point-based designs. An early example of this was DigiScope [1], utilising a transparent see-through display that allowed users to see information and physical objects through a transparent screen. Image-processing solutions have been proposed to allow users to point at the screen or at the physical object behind the screen [2,3]. Notably, Olwal [4] combined see-through displays with depth cameras to examine user’s preference of touch vs. touchless interaction, showing that users prefer touch interactions. Waving gestures have previously been used to control applications (e.g. Sony’s EyeToy), but given its commercial potential, there have been few formal evaluations of such display systems in real-world settings. Public retail environments provide constraints that are quite different to the use of displays in other settings. Even non- interactive shop windows are explicitly intended to encourage multi-participant bystander viewing, and shop window real-estate cannot easily be designed for single users. Indeed, there is likely to be value in encouraging bystanders to become active participants in an interaction. The use of external windows as interactive displays is also problematic; touch-based interaction will smear the glass, making the items on displays less inviting, but also and at the same time, a dirty surface will make interaction unhygienic and potentially less inviting. Shop windows are also usually very large and interacting across an entire shop window by touch may be physically demanding. Finally, the external view of a shop is valuable retail space, and making it an enjoyable and attractive location is important, while bland forms of interaction are likely to lessen their impact as retail spaces. As a step towards understanding user interactions in a public setting with see-through displays, we designed and deployed the WaveWindow, an interactive DVD display, in a retail setting at theatre/restaurant complex in the UK (see Fig. 1, left). In this paper we report the results of a user study, in which we highlight the nature of user interactions with the system and the forms of social interaction that arose from its context of use. The main contribution of this paper is in understanding how systems requiring ‘expressive’ gestural interactions are used in public places. Our interest is less on its commercial value or application, but more in how the form of interactivity and context of its use conspires to shape individual and social interaction. This paper follows Peltonen et al. [9] who describe a week- long evaluation of CityWall, a large public display that bears similarities to WaveWindow. This was placed in a Figure 1: Left: WaveWindow in use, Right: user interface Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. ITS’10, November 7–10, 2010, Saarbrücken, Germany. Copyright 2010 ACM 978-1-4503-0399-6/10/11...$10.00.