KSPC (Keystrokes per Character) as a Characteristic of Text Entry Techniques

Abstract

KSPC is the number of keystrokes, on average, to generate each character of text in a given language using a given text entry technique. We systematically describe the calculation of KSPC and provide examples across a variety of text entry techniques. Values for English range from about 10 for methods using only cursor keys and a select key to about 0.5 for word prediction techniques. It is demonstrated that KSPC is useful for a priori analyses, thereby supporting the characterisation and comparison of text entry methods before labour-intensive implementations and evaluations.KeywordsCandidate ListSpace CharacterText EntryWord StemVirtual KeyboardThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.