Specialized elements of hardware and software, connected by wires, radio waves and infrared, will be so ubiquitous that no one will notice their presence.

(Reprinted with permission. Copyright (c) 1991 by Scientific American, Inc. All rights reserved. This article first appeared in Scientific American, Vol. 265, No. 3 (September 1991), pp. 94-104)

Ubiquitous computing enhances computer use by making many computers available throughout the physical environment, while making them effectively invisible to the user. This article explains what is new and different about the computer science involved in ubiquitous computing. First, it provides a brief overview of ubiquitous computing, then elaborates through a series of examples drawn from various subdisciplines of computer science: hardware components (e.g., chips), network protocols, interaction substrates (e.g., software for screens and pens), applications, privacy, and computational methods. Ubiquitous computing offers a framework for new and exciting research across the spectrum of computer science.

(Reprinted with permission. Copyright (c) 1993 by The Association for Computing Machinery, Inc. All rights reserved. This article originally appeared in Communications of the ACM, Vol. 36, No. 7 (July 1993), Pages 75-84.)

As computing devices become more specialized, the user plays an increasingly important role in defining requirements. User expectations for hand-held devices are substantially different from desktop computers. Users expect instantaneous responsiveness as well as intuitive operation. With the advent of rapid design methodologies and rapid fabrication technologies, it is possible to construct fully customized systems in a matter of months. Carnegie Mellon University has developed a User-Centered Interdisciplinary Concurrent System Design Methodology (UICSM) that takes teams of electrical engineers, mechanical engineers, computer scientists, industrial designers, and human computer interaction students who work with an end-user to generate a complete prototype system during a four-month long course. The methodology is web-based and defines intermediary design products that document the evolution of the design. These products are posted on the web so that even remote designers and end-users can participate in the design activities. The design methodology proceeds through three phases: conceptual design, detailed design, and implementation. End-users critique the design at each phase. In addition, simulated and real application tasks provide further focus for design evaluation. The methodology has been used in designing over a dozen wearable computers with diverse applications ranging from inspection and maintenance of heavy transportation vehicles to augmented reality in manufacturing and plant operations. The methodology includes monitoring and evaluation of the design process. While the complexity of the prototype artifacts has increased by over two orders of magnitude, the total design effort has increased by less than a factor of two. This paper describes the methodology and illustrates its effectiveness by describing three recent designs and summarizing their design activities.