As users become increasingly used to touchscreens on their phones, the accuracy of the screen's sensing ability begins to become more and more a factor in ease of use and overall satisfaction. A recent test by Moto Development Labs (apparently no connection to Motorola) seems to give the edge to the iPhone's touchscreen: it beat out the Motorola Droid, the HTC Droid Eris and the Google Nexus One (manufactured by HTC) in touch accuracy.
Moto Labs used a fairly simple method: drawing a diagonal pattern of straight lines very slowly across the screen of each test phone. If the sensing is accurate, the resulting drawing should be made up of straight, unbroken lines, rather than wavy lines. Most of the tests showed the iPhone drawing clear, orderly lines across most of the screen area, though distorting to curves and losing sensitivity at the edges of the screen. The Nexus One and DROID Eris gave good results, though worse than the iPhone overall, ending up with mostly straight lines and maintaining sensitivity out to the edges. The Motorola DROID gave the poorest results, with all tests showing wavy or stair-stepped lines.
The design and consulting firm, with offices in San Francisco and Hong Kong, imputed the results to some combination of coarse sensor grid, sample rate and/or software:
On inferior touchscreens, itís basically impossible to draw straight lines. Instead, the lines look jagged or zig-zag, no matter how slowly you go, because the sensor size is too big, the touch-sampling rate is too low, and/or the algorithms that convert gestures into images are too non-linear to faithfully represent user inputs.
image via Moto Labs