Mobile user interface mechanics

By Andreas Constantinou, Ph.D. Research Director at VisionMobile

The user experience (UX) is probably the most talked-about topic in the mobile industry, probably because we all have suggestions about how it can be improved, especially in the post-iPhone era. The (graphical) user interface has been the aspect of the UX which has garnered most attention. However, few people have actually suggested what the UI really is or how it works. What are its mechanics, or what makes the UI tick?

User interface = user-facing applications

The user interface is made of a series of software applications; the idle screen, the call logs, the dialler, the menu app, the inbox, the camera app, the browser, the music player, games or other downloaded applications. The ‘user journey’ is comprised of navigating in and out of different applications all of which collectively make up our perception of the phone’s UI.

The handset OEM integrates the applications horizontally into each other, so that the end result is a seamless flow that hides the application boundaries. The following diagram is a graphical illustration of the user journey in the form of a circle, with selected core apps shown as an example.

The diagram illustrates several important properties of the user journey, as the user travels across the device UI:

• The idle screen forms the beginning and end of each task or action
• The core applications, i.e. idle screen, call log, dialler, menu and sms/inbox applications take up the lion’s share of the user journey.
• The arc length is proportional to the commercial importance of each application; the more an application is used, the more the ‘usage surface’ and the commercial value of the inventory that it exposes.

Core vs downloadable applications

Another important notion in the mechanics of the user interface is the distinction between core (embedded) and downloadable apps.

Core apps form the vast majority of the user journey and are pre-loaded (embedded) into the handset ROM at the point of manufacture. Core applications are typically the idle screen, call log, dialler, main menu, settings menu, browser, inbox, calendar, contacts, camera and multimedia player.

Downloadable applications are all apps that can be downloaded post-sales, i.e. by the user.

There are fundamental differences between core and downloadable apps; core apps are highly interconnected horizontally, making for a seamless user experience, but being very hard to maintain and update. Due to legacy device development processes, core apps are open only to 2nd party developers (the high 10s of OEM software partners) and written using legacy software development platforms (RTOS tool chains and C/C++.)

Blurring boundaries and the future of apps

One of the most interesting developments in the mobile handset industry is how traditional barriers relating to UI technologies have begun to blur:

• modular software management technologies allow updating of core apps post-sales, and open up a market for complete UI renewal, which is purchased and updated post-sales.
• Android and WebOS offer a simplified application environment for core apps which is open to all 3rd parties. Should the OEM allow it, the user can replace their address book with a premium 3rd party version.
• Core apps are increasingly integrated to the network and internet cloud, as is the case with the social address books first featured in H3G’s INQ mobile phones.

And we’ve only seen the tip of the UI iceberg...

Andreas Constantinou, Ph.D. twitter: @andreascon [Andreas is Research Director at VisionMobile, an analyst firm advising on the trends in mobile software and service platforms]