In a recent issue of interactions, Vehicle User Interfaces  were given a thorough discussion which included areas to focus and improve upon when developing and using these specialized interfaces. However, there is a somewhat neglected art that is now reappearing in computing circles which could provide substantial new functionality and value in this market: integration.
In theory, plug-and-play has been around since before Windows 95 (the actual term appearing at roughly the same time as the launch of Windows 95 which listed it as a feature), but in reality the functionality is not nearly up to the moniker. In most cases, for example, you need two installation CDs, a reboot, and a custom program from the manufacturer only before a device is accessible.
Apple Computer has implemented this feature transparently in a strategy they've branded, "The Digital Hub."  When you plug in a compatible devicecellular phone, iPod, or Palm devicethe shared data is synchronized easily and without the hassle of coordinating separate applications such as Address Book and iCal, thanks to the iSync utility. This tool is installed by default as a bundled application with Mac OS X, and requires no additional installations such as software and drivers. All other implementation details are abstracted out by an elegant UI in which a user simply chooses what to synchronize the next time a device is plugged in, provided the device is detected along its given communications medium (be it Bluetooth, FireWire, or USB.) A cellular phone, for example, picks up the numbers and pictures of friends so the next time it rings, you see a picture of your significant other instead of a string of numbers, but without spending hours configuring, downloading, installing, or emailing items around.
Why do I mention this with regard to VUI design? Because smart integration with existing technologies could be the key to widespread adoption of VUI and, thus, its automotive manufacturer. Consider an iPod or similar device which carries address book data, calendar and to-do list data, and possibly playlists. By interfacing with this device a VUI would be able to customize itself on the fly using the most up-to-date information, synchronized automatically each time the iPod was plugged in, providing a custom musical environment organized by the user.
Similarly, other technologies such as Bluetooth,1 could be used to integrate a cellular phone address book, lists, calendars, and even picture data into a VUI's integrated phone or PIM (personal information management) functionality. The ability to take a picture from the cellular phone and turn it into a clickable onscreen button with an image of the person is relatively easy and is an improvement in both integration and metaphor. With such a button, a two-click one-second motion is possible to make a phone call with motor memory intact: Imagine a dedicated phone button that pulls up the phone interface, with groups of smiling faces; click on one and the VUI would handle the supplemental actions of informing the driver which person was selected, stating audibly: "dialing Sarah at 555-2451," while handling all the lower-level dialing actions without further driver/passenger impetus.
From a safety and standardization standpoint another feature of integrating a cellular phone into the VUI for user preferences is that cellular phones all contain the correct emergency number (such as 911) which allows the VUI to automatically detect and use the correct local number from the phone, without any configuration by the user or external connection to a satellite or third-party service.
Another ancillary benefit of using an iPod or other portable device with either a hard drive or flash memory is that it would allow the VUI itself to save a small preference file on the device, independent of the vehicle's onboard storage. If a battery dies, or the equipment fails, or some other catastrophe, the data would be preserved on the secondary device(s) previously synchronized with the VUI. Imagine that instead of resetting all the stations after getting your car back from the shop, you could just plug and drive, as if you'd never had a problem that required repairs.
From a user-centered standpoint this integration provides an easier experience when using the VUI. When pulling up a map-based interface the VUI can helpfully provide starting locations based on home or work addresses or respond to simple commands to link one address to another, without having to provide exact addresses that you might not immediately recall or want to search for in a planner, phone, or other accessory.
Indeed, even configuring the general features such as phone and map preferences and others could be handed off to an external computer. Adding this amount of complexity, however, could adversely affect the usefulness of such integration, much as charging an electric car from home, even in limited testing , affected the adoption of an otherwise good vehicle.
While this general concept of vehicles and media devices has been pursued by Apple and VW in a marketing campaign called "Pods Unite!"  much more is possible when integration aids the user, increasing functionality, usability, and safety.
Lead Software Engineer
Infinite Nexus Software
©2004 ACM 1072-5220/04/0500 $5.00
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