User Interfaces to Come

The cellular mobile telephone user interface has evolved since the early 1980s without strong de facto or other standards. Where related standards exist, such as the ITU standard^[*] for the alphanumeric keypad layout, they are indeed widely applied. In the absence of standards, user interface conventions have arisen by way of response to the complexity of the user experience.

The latter consists of handset and network features, applications, information visualization conventions, menu navigation and function access, and the “feel” of the device in use. The items in this list relate to human behaviors that are largely learned. We continue to believe that the user interface should be developed through evolution, not revolution. We also recognize that manufacturers won’t stop introducing revolutionary UI concepts for handheld gadgets, and attractive elements of these concepts may eventually find their way into high-volume mainstream mobile communications devices. The mobile phone user interface will evolve through the push and pull of new UI conventions, technologies, and design improvements brought forward, for diverse and sometimes conflicting reasons, by device manufacturers, application developers, and service providers.

There are already several changes in mobile phone UI development that will influence UI styles. Many of them also crop up in related markets such as PDAs, games, or desktop GUIs. Even though we expect gradual change to prevail over completely novel UI solutions, the limits of evolution and the flexibility of our UI styles will be challenged by some of these trends.

• Color displays. Markets like that in Japan have extensively transitioned to color displays. At the time of writing, a similar transition is taking place in Western markets. This development is very reminiscent of growth patterns in the laptop computer business and later in the PDA industry.

• Input and control device proliferation. Many phones are now outfitted with scaled-down joysticks. We introduced the roller. Some large-screen smartphones incorporate touchscreens. All these improvements are needed to support more direct-manipulation user interfaces. Direct manipulation, in turn, supports content-intensive applications and services such as imaging and multimedia messaging. From a UI style standpoint, it is not at all obvious whether a direct-manipulation UI controlled by a pointing device can be designed based on conventional menu navigation UI styles. Our UI concept creation experiences indicate that totally new UI style types may be needed if and when direct-manipulation and larger screens arrive in mobile devices. Their advent, however, raises an even bigger question: What is the right balance between portability and direct manipulation on a large display? It may turn out that consumers do not want to carry a device large enough to support a true point-and-click direct-manipulation interface.

• Higher-quality audio. Both voice control and audio output will improve. Voice control will expand from dialing preprogrammed names in memory to speaker-independent digit and name dialing. When it does, more freeform voice commands will be possible. It is good to keep in mind, though, that voice control has been seen as one of the next-generation UI technologies and post-GUI silver bullets for a very long time. What we mean by “improvement” today is that audio output is in the process of migrating from monophonic beeps to polyphonic tones, Musical Instrument Digital Interface (MIDI), and stereophonic audio.

• Seamless user experiences. Bringing the mobile Internet to the masses requires services that can be accessed intuitively and seamlessly via the terminal. Ideally consumers should see no difference or degradation in their Internet experience resulting from the source of content, be it the device, an operator-provided network service, or a freely accessible Internet service.

• Personalization. Handset personalization is in full swing with downloadable ringing tones, graphics, games, and user-changeable phone covers. This trend will continue to grow as we start to see user-changeable color themes and downloadable UI skins, screensavers, and other personalization possibilities in the handsets.

• Replacement customers. More and more customers are purchasing not their first mobile phone but their third, fourth, or maybe tenth. These people already know what to expect; they are willing to change brand if the previous model was a disappointment, but happy to stick with it if the previous model was a good fit.

• User interface platformization. We may not see the strict separation of device hardware and software that typifies the PC business, but proprietary user interfaces are gradually becoming more open and more standardized to facilitate service and application creation. The development and integration of a new mobile phone is, and is likely to remain, a more complex proposition than a new PC model.

• New-product categories. The conventional, mainstream mobile phone user interface will progress in organic increments, but in the emerging product categories there is room for revolution. New interoperability technologies like Bluetooth may facilitate the creation of multipart devices having radically different UI paradigms. New customer segments may also have radically different customer needs, and introduce new usage scenarios.

There is no dominant design in cellular mobile telephones user interfaces, but, as a market leader, Nokia has created user interfaces that come closest: Navi-key and Series 30. The maturing marketplace and the needs for more open UI platforms place special constraints on our UI development roadmaps. By strategically balancing the level of evolutionary and revolutionary UI development, we can engineer hundreds of millions of positive user experiences—or else we can fail miserably. Naturally the “right” balance is highly dependent on customer and product segmentation; in many segments customers prefer a clear continuum from their previous phone models, and in some other markets more radical revolution may, and actually should, take place.

^[*]D. Hix and H. R. Hartson, Developing User Interfaces: Ensuring Usability through Product and Process. New York: Wiley, 1993.