BetweenKeys: Looking for room between keys

Abstract

A conventional keyboard has a large footprint because it should serve numerous functions with independent keys. With demand for smaller keyboards, the present paper analyzes a practical method that leverages overlap of two ordinary keys and may reduce the keyboard size. By analyzing overlap frequencies and key stroke timings in normal use, we investigated whether key overlaps are practically usable. From the results, four pairs are recommended that are practically available and preferred by users. Hangul / English mode transition is described as an application.