I. Scott MacKenzie (2002). “KSPC (Keystrokes per Character) as a Characteristic of Text Entry Techniques” (PDF). Proceedings of MobileHCI 2002. http://www.yorku.ca/mack/hcimobile02.PDF. "Values [of KSPC] 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"
I. Scott MacKenzie (2002). “KSPC (Keystrokes per Character) as a Characteristic of Text Entry Techniques” (PDF). Proceedings of MobileHCI 2002. http://www.yorku.ca/mack/hcimobile02.PDF. "Values [of KSPC] 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"
