An In-Depth Look into the Text Entry User Experience on the iPhone

Abstract

Sixty volunteers participated in a within-groups study aimed at evaluating the text entry system on the iPhone. Participants completed multiple structured text entry tasks on the iPhone's soft keyboard and two hard-key mobile phone keypads - QWERTY and numeric. The message completion time and number of errors per message were collected to identify potential differences in performance between the devices. Participants made significantly more total errors on the iPhone than on the hard-key numeric and QWERTY phones. When using the iPhone, iPhone owners left more errors in the completed messages than hard-key QWERTY device owners. Furthermore, novice and expert iPhone users did not differ in terms of the number of errors they made on the iPhone. A detailed analysis of the iPhone keyboard was also conducted. iPhone key hit rates were all above 90%, while hit rates for a hard-key QWERTY keypad were above 96%. Keys on the iPhone also had higher false alarm rates.