Investigating the biomechanical hand and its role in designing interactions. Rachel Eardley, Dr Steve Gill, Dr Stephen Thompson Cardiff Metropolitan University: Cardiff School of Art & Design Western Avenue, Cardiff, CF5 2YB, United Kingdom rachel@racheleardley.net, sjgill@cardiffmet.ac.uk, sthompson@cardiffmet.ac.uk ABSTRACT This paper outlines a PhD research project that questions the design of technology by investigating the human hand as a biomechanical tool. The intention is to research through a human centered design process focused on the hand, potential ways for the human to naturally interact with technology. Author Keywords Hand, Interaction design, Design, HCI. ACM Classification Keywords H5.m. Information interfaces and presentation (e.g., HCI): Miscellaneous. INTRODUCTION Perhaps the most natural and instinctive way in which human beings physically interact with the world is by means of the human hand. With the way the human body has itself influenced our understandings of mechanical technology it is rather easy to think of the human hand as a form of biomechanical tool. It is a tool we can, (disability aside) use without thinking about. This ease of use provides in turn an aspirational model for many interaction designers who would like us to be able to use technology with the same fluency as the way in which we use our hands. However, it appears as if few interaction designers comprehend the full complexity of the relationship between the hand, cognition, the rest of the body and the physical world as it is both apprehended and imagined. It would appear that the human hand plays a complex role, not just within HCI but also the human’s everyday activities. In his book “The hand”, Frank Wilson argues that humans rarely notices the ‘skill’ with which the hand performs daily, not just to use computer technology but by simply lifting the fork to our mouths so that we can eat [1]. Today, much of our technology has been created with the intended method of interaction being that of the human hand, but does this technology truly allow for the affordances that the multi-functional biomechanical human hand enables? Bret Victor argues that it does not and that today’s technology of touch screen interaction misses out on the true capability of the human hand [2]. DESIGNING FOR THE BIOMECHANICAL HAND If we see the hand as bio-tool that has evolved from a locomotive device once used to travel through trees, into the manipulative device used every day by the bipedal modern human [1] then perhaps an understanding of this evolved hand’s abilities is needed to truly design intuitive interactions. A mechanical mechanism Many designers have studied the human hand as a potential mechanical mechanism. Industrial designers such as Henry Dreyfuss have used the human hand’s mechanical structure, its measurements ’anthropometrics’ and its range of movement ‘ergonomics’ as tools to empower the design of physical products [3]. It is with these measurements that Dreyfuss and associates created a lexicon on how to create physical mechanical controls for the human hand. This included objects such as keypads, rotary knobs, push buttons, joysticks and handles [4]. Where as much of the early HCI research literature investigated the mechanics of the hand through efficiency. Defining good interaction design through the speed of a finger press offset by the least amount of human error [5,6]. A sensory device Design researchers as Hemmert have attempted to utilise the hand’s sensors by creating a form of communication through the shifting of physical weight and the changing of shape of a handheld object [7]. Others have attempted to modify existing technology by adding sensory feed back to touchscreen devices [8, 9]. There have also been attempts to create a more compelling digital world interaction: Researchers have added feedback through mechanical technologies such as actuators in gloves [10] and the commercial game industry have developed handheld vibration feedback devices such as the Nintendo Wii remote [11]. As a gestural communication tool The hand’s natural range of movement has enabled many researchers to create interaction techniques through gesture. These interaction methods including both surface based and ‘in air’ gestures. Surface technology such as Touchscreen interaction (tabletops, tablets and mobile phones) use direct manipulation techniques, where the hand connects with the screen. Researchers have attempted to create a lexicon or 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. DIS 2012, June 11-15, 2012, Newcastle, UK. Copyright 2012 ACM 978-1-4503-1210-3/12/06...$10.00.