Intuitive interface

Open any computer program and you are subjected to an array of buttons, fonts and layouts that are usually fixed and unchangeable. Such designs are especially frustrating for disabled people, older people and anyone who has trouble controlling a mouse.

A new approach to design, developed by researchers at the University of Washington, would put each person through a brief skills test and then generate a mathematically-based version of the user interface optimised for his or her vision and motor abilities.

The system, called Supple, begins with a one-time assessment of a person's mouse pointing, dragging and clicking skills. A ring of dots appears on the screen and as each dot lights up, the user must quickly click on it.

The task is repeated with different-sized dots. Other prompts ask the participant to click and drag, select from a list, and click repeatedly on one spot. Participants can move the cursor using any type of device. The test takes about 20 minutes for an able-bodied person or up to 90 minutes for a person with motor disabilities.

An optimisation program then calculates how long it would take the person to complete various computer tasks, and in a couple of seconds it creates an interface that maximises that person's accuracy and speed when using a particular program.

Researchers tested the system last summer on six able-bodied people and 11 people with motor impairments. The resulting interfaces showed one size definitely did not fit all.

A man with severe cerebral palsy used his chin to control a trackball and could move the pointer quickly but with spasm-like movements. Based on his skills test, Supple generated a user interface where all the targets were bigger than normal, and lists were expanded to minimise scrolling.

By contrast, a woman with muscular dystrophy used both hands to move a mouse. She could make very precise movements but moved the cursor very slowly and with great effort because of weak muscles. Based on her results, Supple automatically generated an interface with small buttons and a compressed layout.

Tests showed the system closed the performance gap between disabled and able-bodied users by 62 per cent, and disabled users strongly preferred the automatically generated interfaces.