Designing for Usable Disappearance – Mediating Coherence, Scope, and Orientation Thorsten Prante GMD – German National Research Center for Information Technology IPSI – Integrated Publication and Information Systems Institute Dolivostr. 15, Darmstadt, Germany ++49(0)6151-869-924 thorsten.prante@gmd.de ABSTRACT In this paper, I emphazise on the users’ experience when faced to disappearing user interfaces. I will start out, confronting potential conveniences of ubiquitous computing and related visions to possible shortcomings in their implementation due to design flaws. Three key issues for user-centered design of disappearing interfaces in ubiquitous computing are proposed, namely perceived coherence of computerized devices, awareness of the scope of effects resulting from one’s interactions and support for orientation. I will illustrate these issues by use of examples, arguing that intuitively regognizing the potentials of a designed network of computational artifacts will be crucial for the users’ acceptance of UbiCom environments. Therefore, I will promote the careful design of human-perceived context, which uses familiar symbols and affordances to make user interfaces and options visible. I briefly refer to components of the ‘product language’ before presenting selected features of roomware environments and pointing to future research. Keywords ubiquitous computing, coherent experience, human- perceived context, U 2 I design, computational artifacts, calm technoloy, convenience INTRODUCTION The vision of ubiquitous computing (UbiCom) promotes that our everyday environment will be interwoven with and augmented by a multitude of interconnected computational artifacts. The ultimate goal is to make “everything faster and easier to do (...) because ease of use makes an enormous difference” [20]. Information technology (IT) will therefore disappear into the background (as electric motors did), where disappearance denotes true invisibility, transparency, or subordination by other aspects [4] as it has become true for electric motors (“UbiMot”): First, they are often truly invisible, e.g., in cars. Second, there are transparent tools based on electric motors. Third, we take their functional aspects for granted, but it still matters how the so-enhanced objects and their UI do look like. The envisioned progress of technology towards UbiCom will introduce more calm into human-computer interaction (HCI) through “engaging both the center and the periphery of our attention, and in fact moving back and forth between the two” [21]. UbiCom technology is supposed to support us in the fulfilment of our everyday tasks, being less disturbing and introducing ease, e.g., by empowering the networked devices, but also necessitates introducing a more conscious user interface design (UI design) in a broader sense. UI design for UbiCom (U 2 I design) requires the design of hybrid artifacts and environments for a coherent and engaging experience. In designing Roomware ® for Cooperative Buildings this has been approached by an integrated design of real, physical, resp. architectural spaces and virtual, resp. digital information spaces [16]. One approach to reducing the complexity of explicit interaction with computers is to complement it with implicit interaction based on perception and interpretation of data provided by, e.g., sensor-equipped devices [12]. By perceiving the situational context (context for short), so called context enabled applications become feasible. They facilitate not only implicit interaction but also the adaption of input needs and output properties to the current situation. Relating to this, it has been discussed how the affordances of physical tokens (e.g. WebStickers [8] and in a more general sense Passengers [6]) and the context they are placed and/or used in, can act as useful cues for users. A framework, namely the Context Toolkit [11], has been introduced to capture helpful abstractions and to provide generic services aiming at facilitating the development and deployment of context-enabled applications. POTENTIAL CONVENIENCES FOR INFORMATION WORK Today’s office work is determined to a large degree by information processing work (information work for short). In relation to a current task, information is searched, gathered, externalized, structured, evaluated, circulated, and (possibly) archived. Vision UbiCom promises augmented environments which facilitate interaction (with information and people) “everywhere”, realized by a layer of IT-based services supposed to enrich the place.