Sarah Pennington

Expected, sensed, and desired: A framework for designing sensing-based interaction

Movements of interfaces can be analyzed in terms of whether they are expected, sensed, and desired. Expected movements are those that users naturally perform; sensed are those that can be measured by a computer; and desired movements are those that are required by a given application. We show how a systematic comparison of expected, sensed, and desired movements, especially with regard to how they do not precisely overlap, can reveal potential problems with an interface and also inspire new features. We describe how this approach has been applied to the design of three interfaces: pointing flashlights at walls and posters in order to play sounds; the Augurscope II, a mobile augmented reality interface for outdoors; and the Drift Table, an item of furniture that uses load sensing to control the display of aerial photographs. We propose that this approach can help to build a bridge between the analytic and inspirational approaches to design and can help designers meet the challenges raised by a diversification of sensing technologies and interface forms, increased mobility, and an emerging focus on technologies for everyday life.

The history tablecloth: illuminating domestic activity

The History Tablecloth is a flexible substrate screen-printed with electroluminescent material forming a grid of lace-like elements. When objects are left on the table, cells beneath them light to form a halo that grows over a period of hours, highlighting the flow of objects in the home. The Tablecloth explores an approach to design that emphasises engaging, open-ended situations over defined utilitarian purposes. Long-term deployment of the History Tablecloth in a volunteer household revealed complex ways that people experienced and interacted with the Tablecloth. Beyond evoking reflection on the flow of objects over a particular table, the Tablecloth served as a ground for interpretative reflection about technology, an asset for social interaction, and an aesthetic object. Even behaviours we saw as system errors were interpreted by the users as interactively rich. Their experience highlights the subtlety of domestic ubiquitous computing, illustrating alternatives to traditional views of technologys domestic role.

Threshold devices: looking out from the home

Threshold devices present information gathered from the homes surroundings to give new views on the domestic situation. We built two prototypes of different threshold devices and studied them in field trials with participant households. The Local Barometer displays online text and images related to the homes locality depending on the local wind conditions to give an impression of the sociocultural surroundings. The Plane Tracker tracks aircraft passing overhead and imagines their flights onscreen to resource an understanding of the homes global links. Our studies indicated that the experiences they provided were compelling, that participants could and did interpret the devices in various ways, that their form designs were appropriate for domestic environments, that using ready-made information contributed to the richness of the experiences, and that situating the information they provided with respect to the home and its locality was important for the ways people engaged with them.

Electronic Furniture for the Curious Home: Assessing Ludic Designs in the Field

Abstract This article describes field trials of 3 electronic furniture prototypes designed to encourage ludic engagement in the home. The Drift Table shows slowly scrolling aerial photography controlled by the weight of the objects on its surface. The History Tablecloth creates slowly growing “halos” around things left on it. The Key Table measures the force with which people put things on it and tilts a picture frame to indicate their mood. The pieces were loaned to different households for periods of 1 to 3 months. Because they were designed for user appropriation, a hypothesis-testing paradigm is inappropriate for evaluating their success. The focus instead was on gathering rich, multilayered accounts of peoples experience through ethnographic observations and documentary videos. The results helped assess the particular designs, draw lessons for ludic design more generally, and reflect on field methods for evaluating open-ended designs.

A new method for auto-calibrated object tracking

Ubiquitous computing technologies which are cheap and easy to use are more likely to be adopted by users beyond the ubiquitous computing community. We present an ultrasonic-only tracking system that is cheap to build, self-calibrating and self-orientating, and has a convenient form factor. The system tracks low-power tags in three dimensions. The tags are smaller than AAA batteries and last up to several years on their power source. The system can be configured to track either multiple near-stationary objects or a single fast moving object. Full test results are provided and use of the system within a home application is discussed.