Intelligent travel devices confuse, distract

Quick interpretation and response by the user is crucial to safety, says usability expert

The ongoing debate about the use of cellphones while driving took a different turn at a Wellington event this month, with even the humble car radio facing scrutiny.

The search to modernise and combine interfaces has complicated even previously simple procedures such as tuning a car radio, said Trent Mankelow of Optimal Usability at a breakfast to mark International Usability Day.

The iDrive “car infotainment computer” (CIC), provided in some BMWs, for instance, presents an initially appealing combination of a large number of functions into one gear-knob-like control, but tuning into a radio station that’s not pre-set requires six steps — a combination of lateral movements, rotations and downward presses of the knob. All the while you could be looking at the display instead of the road, Mankelow said.

The Microsoft version of a similar device, called the Sync is potentially less distracting, since it’s voice-activated. However, telling it to play a music track on your iPod by voice takes longer than doing the same thing by pressing buttons, chiefly because of the time spent waiting for the device to respond.

In some ways it is safer because you’re not taking your eyes off the road, but on the other hand, it distracts your attention for longer, Mankelow said.

Development of voice-actuated stationary telephone systems still leaves much to be desired, said Mankelow. Optimal Usability advised on a telco’s helpdesk system for broadband problems and found there was a natural expectation of “turn-taking” — that user and machine would alternate in their comments. When the service paused for an unduly long time before offering its next comment, the customer thought they were supposed to say something; but this frequently threw the system off its stride.

Shaving the pauses by a fraction of a second much improved the service.

With in-car navigational aids, quick interpretation and response by the user is crucial to safety.

“We did a lot of work with Navman,” said Mankelow. The company usually works with a user in front of a computer screen indoors. “We’re not often in a position where the participant could kill us if they screw up.”

Users can become over-reliant on such systems. Fellow presenter Gerry Gaffney, a Melbourne-based usability specialist, told a story of becoming lost by following the GPS system’s instruction to turn left at the roundabout rather than the hire-car staffer’s hurriedly drawn map that showed the correct path as straight ahead. The human proved right. A series of photographs of motorists driving along rail tracks and into rivers emphasised the point.

Turning to air transport, Mankelow presented readings of user behaviour on airline booking websites, particularly the crucial step of choosing the first menu in search of the answer to an obscure question such as “find the tax component in the price of the ticket” or “order a vegetarian meal”.

If the first step taken is correct, 87% of people complete the task correctly, but only 47% of users who take the wrong first step find their way to the right endpoint.

Optimal Usability used its new Chalkmark tool (Computerworld, November 17) to register where most users clicked.

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