Researchers at the University of Reading conducted three studies with 72 people, with 12 people aged 70 or over, and 12 people with an average age of 23, in each group.

The first study looked at expanding targets, and found that dynamic on-screen targets, such as icons on the computer screen which expand when you move your mouse towards them, provided a 13% improvement in the time older people took to choose a target, compared with the static targets that you typically expect to find on a screen.

The second study compared static with proxy targets, which are targets that are copied and moved closer to the cursor as the user begins to move their mouse near to it. This means that older users can move the mouse, or the cursor, shorter distances on the screen than with static targets. This study found that the proxy targets made the group of older people slower in their responses than when they had to move the mouse towards a static target.

The third study focused on different methods of expanding icons, or targets, on the screen. The researchers found that dynamically expanding targets were found to reduce error rates from the overall average of 15% to 7.4% in the group of older people.

The researchers conclude from these studies that older and younger users do have different responses to static and dynamic targets on computer screens, as younger people are generally faster in their reactions to static targets than older computer users. The data from this study therefore has important implications for the way websites aimed at an older audience are designed and built using dynamic instead of static targets to improve the usability and accessibility of web pages.

Links:

• Improving computer interaction for older users: an investigation of dynamic on-screen targets. Faustina Hwang, Reading University. (PDF executive summary).