Using a computer mouse or trackball can be a little tricky. You choose the object you want and move it to where you want it, only to have it end up in a different position. This happens to all of us sometimes, and we think little of it. But for people who have a difficult time controlling their movements, this little navigational issue can be a really big problem. Now, researchers at the University of Washington have developed new cursors that make activating objects easier for people with motor disabilities. Jacob Wobbrock is an assistant professor at the University of Washington. He leads the AIM Research Group that developed the cursors. Professor Wobbrock says mouse cursor operations are complex processes that assume things about computer users. He says, "For many people who have poor dexterity, the inability to control their fingers well, maybe pain in their wrists or hand, maybe arthritis -- those assumptions of the average user, they don't hold." The AIM Research Group has developed two cursors. One is called the Pointing Magnifier. Professor Wobbrock says it uses a large circular cursor instead of the traditional arrow pointer. Users can make the circle as big as they like. When the circle is positioned over the target, everything in the circle appears larger, almost filling the whole screen. This makes it easier for the user to click on the object. Inside that magnified view, the user sees the regular point cursor -- the little arrow. And with that they can click on the target they want or they can move the target. The AIM Research Group's Pointing Magnifier software can be downloaded free from the University of Washington website. AIM is short for Accessible, Interactive and Mobile. Professor Wobbrock says the group's main goal is to make information and computer systems more available and easier to use. And he says AIM's work is not just for people with disabilities. People usually think of accessibility as having to do with someone's physical or cognitive state. But Professor Wobbrock says some projects have looked at "situational impairments." These are challenges to accessibility that are caused more by the situation that the computer user is in. An example of this might be trying to walk and use a small mobile device at the same time.

For VOA Special English, I'm Alex Villareal. MP3s, podcasts and transcripts our reports are at voaspecialenglish.com. We're also on Facebook and Twitter at VOA Learning English.