On Being Supple: In Search of Rigor without Rigidity in Meeting New Design and Evaluation Challenges for HCI Practitioners Katherine Isbister Kristina Höök Polytechnic Institute of New York University Swedish Institute of Computer Science Six Metrotech Center, Brooklyn, NY 11201 Box 1263, 16429 Kista, Sweden [email protected] [email protected] ABSTRACT leisure and entertainment uses of technologies mean In this paper, we argue that HCI practitioners are facing that we must stretch and evolve our design thinking to new challenges in design and evaluation that can benefit include support of process values such as fun, enjoy- from the establishment of commonly valued use qualities, ment, emotional engagement, and the like, including with associated strategies for producing and rigorously nonverbal interaction. evaluating work. We present a particular use quality— We believe all these factors make both design and evalu- suppleness—as an example. We describe ways that use ation profoundly more difficult for the following reasons: qualities can help shape design and evaluation process, and propose tactics for the CHI community to use to encourage • We can’t rely on re-using pre-existing interface meta- the evolution of bodies of knowledge around use qualities. phors and strategies because there are too many new variables of use. Author Keywords • It’s hard to create designs without extensive prototyp- Suppleness, evaluation, prototyping, games, mobile, em- ing and iteration. This means teams require new skill bodiment, use qualities. sets and more resources (including time). ACM Classification Keywords • It’s hard to fully appreciate/investigate the results of H.5.2 User interfaces this work (if they are not already a full-blown commer- cial product), so it’s hard for our research community INTRODUCTION to trade notes and build theory and knowledge about As has been remarked by others (e.g. [4]) the last 10 years what we are doing. have presented CHI practitioners with a series of radically • Evaluating the success of these interfaces requires new new challenges/opportunities: measures and ways to preserve context (e.g. social, en- • New contexts of use. Digital technologies are now vironmental) otherwise tests just are not valid for the commonplace in the home, in mobile contexts, and as final use context. part of ongoing social interaction and within complex We see this as one reason for the groundswell of dissatis- social contexts. faction with traditional evaluation methods (e.g. [12]) to • New inputs. Cheap, commercially available cameras address the quality of our work in these new domains. and sensors finally in place with enough consumers Yet our community has a strong empirical foundation. Des- mean we can take seriously the possibilities they pro- pite a strong undercurrent of structural and theoretical cri- vide to use for designing more nuanced and rich inter- tique, that is healthy in any case, we believe the vast ma- actions. jority of CHI attendees—researchers and practitioners— • Great interest in new types of ‘tasks’. The growth of care deeply about grounding our work in rich observations of what does and doesn’t work, toward helping one another to design graceful and appropriate interfaces and interac- Permission to make digital or hard copies of all or part of this work for tions. We desire rigor in our practice. And we also desire personal or classroom use is granted without fee provided that copies are the ability to extend and apply findings from individual not made or distributed for profit or commercial advantage and that copies projects to others—we don’t want to have to reinvent the 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 process and practice as we go. specific permission and/or a fee. CHI 2009, April 4–9, 2009, Boston, Massachusetts, USA. The authors believe a crucial first step toward meeting these Copyright 2009 ACM 978-1-60558-246-7/09/04...$5.00. new challenges is to cling closely to the rich end experience that we are trying to produce (a tactic that has become in- ! fluential in recent HCI theory—e.g. [23]), then moving novel approaches for HCI-researchers to work in this field from the desired experience to an analysis of what makes it practically and with rigor. so and how it is crafted, toward extensible and applicable knowledge in broader contexts. If we ground ourselves in Research Examples: Tales of Chasing Suppleness the fundamental experiential qualities we want to evoke for Our interest in use qualities emerged from ongoing challen- those who engage with our products, we believe it is pos- ges we have faced in crafting research prototypes meant to sible to form a fresh understanding of how we can manage engage people in rich and subtle ways. What follows here to shape these qualities, and how we can share our results are brief descriptions of design issues that arose in the con- with others and create systematic and helpful practices for text of several projects, that help to illuminate the use evoking and evaluating such qualities. quality we ended up defining using Löwgren’s approach. We are inspired by the work of Jonas Löwgren [21, 22]. He Designing SenToy. SenToy is a plush toy with sensors in- has worked with colleagues to articulate a set of ‘use’ quali- side the body [24], see Figure 1. By gesturing with SenToy, ties of what he terms digital artefacts. These use qualities players control their avatar in a game. The six different ges- were shaped as a frame of reference for interaction design- tures players can perform with SenToy were designed to ers to use in developing their practice. Löwgren and resemble emotional, physical experiences. Shaking the doll Stolterman explain that use qualities offer the value of ‘arti- angrily back and forth makes the avatar in the game angry. culation’ of aims, and are not meant to be a checklist or Quickly pulling the doll backwards, as if feeling surprised, taxonomy but instead ‘proposed tools for questioning, el- makes the avatar surprised. aboration, and making informed choices in thoughtful inter- In our first studies of SenToy, it worked in many ways as action design’ [p. 104, 22]. The idea is to set up touch we had hoped for. Users became absorbed by the game and points in dialog ‘with other designers and design theorists, their interaction through the doll. Their physical engage- as well as with design situations and the stakeholders in- ment showed how they both acted out their involvement volved in them.’ They note that the ‘main purpose of pro- through the doll, but also how they became very physical duct quality articulation is to develop the ability to make also in imitating the movements and expressions of their judgments, which constitute a thoughtful approach to avatar. But unfortunately, in this first study, we discovered understanding the qualities of digital artefacts’ [p. 104, 22]. that the sensors and the wires inside SenToy were easily We find Löwgren’s concept helpful1 in pointing the way destroyed. The design team therefore decided to put a skele- toward a new form of rigor that provides HCI practitioners ton inside the doll to keep all the sensors in place. The with more flexibility. We believe use qualities can be taken skeleton was hard and only allowed for rigid, hard move- up as pole stars to navigate by for designers and those who ments. It removed the floppy feeling of the doll and it be- evaluate their work, as well as for end users and those who came quite heavy. This changed the entire experience of the critique on their behalf (such as technology journalists). interaction. The sense of being one with the avatar went away. A more flexible skeleton would have allowed us to We will illustrate what we mean in this paper, by defining 2 get back to the interaction we wanted, but the project could and explicating a new use quality—suppleness [13]—that not afford creating yet another version of the system. In this seems to come up in many recent user experiences that have case, what we’ve begun calling ‘suppleness’ was not privi- the characteristics we outlined in this introduction (new leged in the final research outcomes, yet we felt it as a loss contexts of use, new inputs, new types of task). We use this in the end experience for users. quality as a touchstone for discussing how our field could orient towards providing useful design knowledge to practi- Designing eMoto. Another project that provided unex- tioners and still address the complexities of the new, ex- pected challenges in terms of the physical form factor of perience-based, design situations. This paper therefore both our prototype system was in the mobile messaging system defines what a supple design quality is, and through defin- eMoto, see Figure 1. [26]. The system made use of the sty- ing it, tries to shed some light on research methods and lus that comes with certain mobile phones, extending it with some sensors to allow users to express themselves physi- cally. By gesturing with the pen, using pressure and move- 1 There are other HCI practitioners who have introduced ment, users changed the background to their text message to terms to put names on hard-to-describe usability qualities— have colours, shapes and animations resembling their phys- e.g. Green and Petre’s Cognitive Dimensions [11]—we ical movements. Hard pressure and energetic movements found Löwgren’s approach and taxonomy particularly help- with the stylus rendered a strong red colour with a large set ful, but the reader may find others that work well for their of animated small, sharp-edged shapes moving in a jerky purposes.