Published in: Personal and Ubiquitous Computing, vol. 6, no. 4, 2002, pp. 237-244

Wireless Application Protocol (WAP) phones are a growing relevant part of the mobile market, and the number of offered WAP services is rapidly increasing. Usability is crucial for these services, which must be easily operated on small screens and keyboards. Unfortunately, there are very few published studies on the evaluation of WAP devices and services on users. This paper presents a user study that evaluates two important interface design choices for WAP services (implementation of single-choice selection and navigation among the different cards of a WAP site) which have not been thoroughly investigated neither in the literature nor in design practice.