Abstract
Portable terminals such as Personal Digital Assistants (PDAs) and mobile phones are very convenient because it is possible to use them anytime and anywhere. Portable devices can be used for efficiently supplying various modes of information ranging from text and images to and audio and movies at the user's discretion. This mode of information delivery has many advantages. However, priority has been given to the technical development of systems for portable devices, while design aspects that focus on the user have been neglected. User-centered design (UCD) places the user at the center of the design process. This paper reports on how UCD should be an integral part of any design process by detailing research conducted in Japan on viewing support systems using mobile phones and PDAs in art museums.