Chapter 1: User Interface Styles

Overview

Harri Kiljander and Johanna Järnström

An estimated 423 million mobile phones were sold globally in the year 2002. The mobile phone has become the information appliance that keeps people in touch. Among phone manufacturers, user interface is one of the key elements in the fight for customers. To the individual who purchases a mobile phone, a good user interface means convenience and an intuitive and easy access to the most frequently needed calling functions. It creates positive word of mouth and encourages brand loyalty when it's time for the customer to purchase a new phone. To the mobile operator, a good user interface leads to increased usage of the operator's wireless services and to reduced need for customer support.

Unlike the personal computer industry, the cellular industry has no standard user interface. Practically all mobile handset manufacturers are using their own UI solutions and conventions. This freedom offers wider choices to customers, lets manufacturers gradually develop and improve the user experience, and in general makes the user interface a competitive asset in the race for market dominance.

Usability and user-centered design are considered core competencies at Nokia. When we're talking about usable mobile phone user interfaces, the key artifact we want to keep in focus is the user interface style. (Some experts in the human-computer interaction field use the term interaction style). By this we mean the UI design conventions applied throughout a handset. This chapter describes the concept of UI style, briefly explains how to align customer segments with the appropriate user interfaces, discusses how user interface styles are created and evolved, and ponders the ways that the cellular mobile telephone user interface may change in the near future. Details of the UI styles themselves, namely, screen layouts, control key combinations, and menu structures, are discussed in Chap. 2.