Seeing the Invisible shabeh esearch ivision ley Berkeley, CA 94720-1776, USA tion of in-unity. We gent attrib-ight be, in propose a sibility-in-ely free of f physical, l infrastructures to become tacit in the thoughts and actions of human actors. Underlying our approach is the belief that invisi-bility is fundamentally a phenomenological human construct, an experience of he world that is socially and psychologically created by humans as research e” or “fade literally, human-searchers to our con-k through ed, so fit-anan ting tech-d Harrison [4] envision “a perceived mputer is ruc-echnology where today’s personal computer has disappeared into invisibility.” While in many ways inspiring, these concepts, when taken in aggregate, are ripe with inconsistency. There is a distinct aesthetic appeal to rendering systems physi-cally invisible, but total invisibility, and the lack of feedback and control that implies, is obviously undesirable. From the psychological perspective, designing calm or ubiquitous technologies is clearly a valuable goal, but just what factors are involved Jeffrey Heer, Peter KhooGroup for User Interface RComputer Science DUniversity of California, Berke{jheer, pkhoosh}@cs.berkeley.edu Abstract. In this article we attempt a closer examination of the novisibility as it has been used within the ubiquitous computing commseek to tease apart various understandings of invisibility as an emerute of technology use, examining what true “invisible technology” mwhat ways it is beneficial, and how it might be designed for. We theoretical model consisting of two complementary concepts: inviuse, the experience of direct interaction with artifacts and tools largconscious monitoring, and infrastructural invisibility, the capacity oorganizational, or technologicabeing in tthey go about their various activities. 1 Introduction The last decade has witnessed the emergence of ubiquitous computing, aeffort seeking to make technology “disappear,” for it to become “invisiblinto the background.” Some researchers address these goals more or lessembedding computation into the environment and attempting to make computer interaction less apparent, or more “calm” and “natural.” Other retreat this metaphorically, talking about designing technologies that fade inceptual background, the goal being the construction of tools that we worrather than work with. Still others conflate both these approaches. Mark Weiser referred to invisible technology as that which is “so imbeddting, so natural, that we use it without even thinking about it” [20]. Satyanaray[15] interprets invisibility as a “complete disappearance of pervasive compunology from a user’s consciousness.” Fishkin, Moran, anprogression towards a more real-world interaction style, where there is no mediation, i.e., an invisible user interface.” Norman [13] writes “The coreally an infrastructure, even though today we treat it as the end object. Infrasttures should be invisible … A user-centered, human-centered humane tin creating and learning such systems are often not elaborated – many times iassumed that these technologies will be amenable to a simple walk-up-anddigm. Pr1t seems -use para-esumably these technologies will leverage our tacit knowledge, but it is s of such t the heart eed to use and infra-al device ach is the struct, an ed by hu- rooted in Merleau-s such as by which make these concepts concrete and relate them to the ubiquitous computing agenda. We then conclude by dispelling nceptions about invisibility and consider how our framework omena in ring them; have been eidegger’s of tools. laborated works by both Winograd and Flores [21] and Dourish [3]. In a modern adaptation of Heidegger’s hammer, Dourish gives the example of computer mouse use: when the some task, it becomes an extension of the body used r the wire artifact in Studies in psychology provide scientific evidence for the phenomena of invisibility-tion in the , Berti and Frassinetti found that the task of bisecting a line in space could highly depend on the tool used. Participants were told to bisect a line in near-space using a laser pointer unclear how much consideration has been given to the nature and sourceknowledge. In this paper we attempt to elaborate two forms of invisibility that lie aof the ubiquitous computing agenda: invisibility-in-use, in which we are “frtechnologies without thinking and so to focus beyond them on new goals,” structural invisibility, “everywhere computing that does not live on a personof any sort, but is in the woodwork everywhere.” Underlying our approbelief that invisibility is fundamentally a phenomenological human conexperience of being in the world that is socially and psychologically creatmans as they go about their various activities. As such, our approach isphenomenological philosophy, including the works of Heidegger [8] andPonty [12], as popularized within human-computer interaction by authorSuchman [18] and Dourish [3]. After introducing these concepts and meansthey can be studied, we present a series of examples to some common miscomight be applied to the design of ubiquitous computing systems. 2 Invisibility-In-Use Ranging from pencils to computers, invisibility-in-use refers to the phenwhich people directly employ tools or concepts without consciously monitowhen people work through their tools rather than with them. These notions the object of philosophical and psychological study at least as early as HBeing and Time [8], in which Heidegger uses the terms zuhanden (ready-to-hand) and vorhaden (present-at-hand) to describe the unconscious and conscious useThe relevance of these concepts to Human-Computer Interaction has been einmouse is used to complete largely unconsciously. However, as soon as the mouse runs off the pad oobstructs motion, it is present-at-hand, becoming consciously present as an use. 2.1 Studying Invisibility-In-Use in-use, suggesting tools can cause a fundamental remapping of how acworld is perceived. In a study of subjects with near-space visual neglect [1] 1 Tacit knowledge: our knowledge and abilities that enter into the production of behaviors and/or the con-stitution of mental states but are not ordinarily accessible to consciousness. (Adapted from the Dictionary of Philosophy of Mind, http://www.artsci.wustl.edu/~philos/MindDict/)and were unsuccessful, but succeeded at the task when performing it in However, when subjects