Paper Reading #10: Enhanced Area Cursors: Reducing Fine Pointing Demands for People with Motor Impairments

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Reference information
Authors: Leah Findlater, Alex Jansen, Kristen Shinohara, Morgan Dixon, Peter Kamb, Joshua Rakita, Jacob O. Wobbrock
Where: UIST 2010, October 3–6, 2010, New York, New York, USA.

Summary
This paper introduced four area cursor designs to improve performance for the motor-impaired. Specifically, these cursors aim to reduce fine pointing and unintended clicks. All four cursors go through two stages: activation and selection. Two use goal crossing, where the user moves a circular area cursor over the desired target and clicks to activate. In the first of these, click-and-cross, Clicking activates the cursor and transforms covered targets into crossing arcs that surround the circular cursor. Crossing these arcs selections that target. The second, corss-and-cross, actually doesn't require clicking to activate the circular cursor, but features an initial red arc that activates when crossed. The other two cursors use magnification, where the user controls an area cursor that when activated, either lowers the mouse gain to allow for easier selection within the bubble (motor-magnifier), or increases the size of the area cursor and all targets inside it without dropping the mouse gain (visual-motor-magnifier).

The click-and-cross (top) and visual-motor-magnifier (bottom) area cursors. 

The left and right images show before and after activation. Source: publication

In the designers' experiment, twelve impaired participants (4 males) and twelve able-bodied participants (12 males) were put through the same tests. The evaluation observed cursor type, target size, target spacing, and target clutter. Time to select targets and error rate were used to evaluate the cursors. The enhanced area cursors did not degrade when size and spacing decreased. The visual-motor-magnifier and click-and-cross cursors were the most successful new designs, reducing selection time for small targets, reducing corrective submovements, and reducing error rate by 70% and 82%, respectively, compared to the point cursor. The cross-and-cross cursor was found to be relatively slow, but beneficial to those who experienced pain from clicking. 

Discussion
This is similar to my previous paper reading on the satellite cursors. But I found this to be much more interesting to read and the implementations to be more intuitive. I also appreciated that the designers aimed to help the motor-impaired. But I thought the group in the user study could have been larger and more diverse. Still, the designers did acknowledge that since the study was conducted in a controlled lab setting that does not reflect a realistic or complex environment.