The iPhone 5S and 5C both unexpectedly underperformed on a test of touchscreen accuracy, performed by Optofidelity.
The test showed that the two models of iPhone were faster than the Galaxy S3, but they were a lot less accurate when it came to their touchscreens.
Optofidelity had a robot touch specific coordinates on each phone’s screen, and measured where the handset had registered the touch.
The iPhones were considerably less accurate than the Galaxy S3 around the edges and at the top of the screen.
This can lead to typing errors, as letters on the edge of the virtual keyboard such as Q and P can get missed due to touchscreen inaccuracy.
The Galaxy had a little bit of inaccuracy around the edges of the screen, but was generally far more accurate, and therefore easy to use, than the iPhones.
Optofidelity suggests testing the accuracy of your smartphone. For example, you could “try to tap the letter P (English keyboard) when your finger is close to the right side of the screen”.