Last year, when iOS 7 debuted, Aubrey Johnson made a contention that users are slower to recognize hollow icons than solid ones. Curt Arledge decided to put that to the test with a custom-built Rails app that tested participants’ ability to recognize icons of the two types, and ran the trial over 1,000 times. His conclusions revealed that Johnson’s assertion could not be supported in fact.

My ultimate conclusion is one that most designers probably felt intuitively upon encountering the solid/hollow debate: designing icons to be both semantically clear and visually attractive is a complex exercise that doesn’t lend itself to simple binary rules. In fact, a closer look at Apple’s Human Interface Guidelines, which lay out its recommendations for solid/hollow icon design, acknowledge that some icons simply won’t work well in both styles.

Read the full post at Viget.com.