Abstract

Mobile devices often utilize touchscreen keyboards for text input. However, due to the lack of tactile feedback and generally small key sizes, users often produce typing errors. Key-target resizing, which dynamically adjusts the underlying target areas of the keys based on their probabilities, can significantly reduce errors, but requires training data in the form of touch points for intended keys. In this paper, we introduce Text Text Revolution (TTR), a game that helps users improve their typing experience on mobile touchscreen keyboards in three ways: first, by providing targeting practice, second, by highlighting areas for improvement, and third, by generating ideal training data for key-target resizing as a side effect of playing the game. In a user study, participants who played 20 rounds of TTR not only improved in accuracy over time, but also generated useful data for key-target resizing. To demonstrate usefulness, we trained key-target resizing on touch points collected from the first 10 rounds, and simulated how participants would have performed had personalized key-target resizing been used in the second 10 rounds. Key-target resizing reduced errors by 21.4%.