Unipad: single stroke text entry with language-based acceleration

A stylus-based text entry technique called Unipad is presented. Unipad combines single-stroke text input with language-based acceleration techniques, including word completion, suffix completion, and frequent word prompting. In a study with ten participants, entry rates averaged 11.6 wpm with 0.90% errors after two hours of practice. In follow-on sessions to establish the expert potential, four users entered "the quick brown fox" phrase repeatedly for four blocks of 15 minutes each. Average rates on the last block ranged from 17.1 to 35.1 wpm, with peak rates reaching 48 wpm.

[1]  Toshiyuki Masui,et al.  An efficient text input method for pen-based computers , 1998, CHI.

[2]  I. Scott MacKenzie,et al.  Measuring errors in text entry tasks: an application of the Levenshtein string distance statistic , 2001, CHI Extended Abstracts.

[3]  Michael D. Byrne,et al.  An Evaluation of Text-Entry in Palm OS – Graffiti and the Virtual Keyboard , 2002 .

[4]  M. H. Heycock,et al.  Papers , 1971, BMJ : British Medical Journal.

[5]  I. Scott MacKenzie,et al.  An empirical investigation of the novice experience with soft keyboards , 2001, Behav. Inf. Technol..

[6]  D. Jeffery Higginbotham,et al.  Evaluation of keystroke savings across five assistive communication technologies , 1992 .

[7]  David Goldberg,et al.  Touch-typing with a stylus , 1993, INTERCHI.

[8]  I. Scott MacKenzie,et al.  KSPC (Keystrokes per Character) as a Characteristic of Text Entry Techniques , 2002, Mobile HCI.

[9]  Poika Isokoski,et al.  Model for unistroke writing time , 2001, CHI.

[10]  Ian H. Witten,et al.  Predictive interfaces: what will they think of next? , 1995 .

[11]  I. Scott MacKenzie,et al.  The design and evaluation of a high-performance soft keyboard , 1999, CHI '99.

[12]  I. Scott MacKenzie,et al.  Phrase sets for evaluating text entry techniques , 2003, CHI Extended Abstracts.

[13]  I. Scott MacKenzie,et al.  The Immediate Usability of Graffiti , 1997, Graphics Interface.

[14]  Ian H. Witten,et al.  The Reactive Keyboard , 1992 .

[15]  A. Edwards Extra-ordinary human-computer interaction: interfaces for users with disabilities , 1995 .

[16]  A. T. Welford,et al.  The fundamentals of skill , 1968 .

[17]  Allen Newell,et al.  The psychology of human-computer interaction , 1983 .

[18]  Gregory D. Abowd,et al.  Interaction techniques for ambiguity resolution in recognition-based interfaces , 2007, SIGGRAPH '07.

[19]  I. Scott MacKenzie,et al.  A comparison of two input methods for keypads on mobile devices , 2004, NordiCHI '04.