An exploratory study of eye typing fundamentals: dwell time, text entry rate, errors, and workload

Although eye typing (typing on an on-screen keyboard via one's eyes as they are tracked by an eye tracker) has been studied for more than three decades now, we still know relatively little about it from the users' point of view. Standard metrics such as words per minute and keystrokes per character yield information only about the effectiveness of the technology and the interaction techniques developed for eye typing. We conducted an extensive study with almost five hours of eye typing per participant and report on extended qualitative and quantitative analysis of the relationship of dwell time, text entry rate, errors made, and workload experienced by the participants. The analysis method is comprehensive and stresses the need to consider different metrics in unison. The results highlight the importance of catering for individual differences and lead to suggestions for improvements in the interface.

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

[2]  Howell O. Istance,et al.  Zooming interfaces!: enhancing the performance of eye controlled pointing devices , 2002, Assets '02.

[3]  I. Scott MacKenzie,et al.  Eye typing using word and letter prediction and a fixation algorithm , 2008, ETRA.

[4]  Päivi Majaranta,et al.  Text Entry by Eye Gaze , 2009 .

[5]  I. Scott MacKenzie,et al.  Metrics for text entry research: an evaluation of MSD and KSPC, and a new unified error metric , 2003, CHI '03.

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

[7]  Poika Isokoski,et al.  Effect of foreign language on text transcription performance: Finns writing English , 2004, NordiCHI '04.

[8]  Jacob O. Wobbrock,et al.  Longitudinal evaluation of discrete consecutive gaze gestures for text entry , 2008, ETRA.

[9]  John Paulin Hansen,et al.  Learning gaze typing: what are the obstacles and what progress to expect? , 2009, Universal Access in the Information Society.

[10]  Poika Isokoski,et al.  Text input methods for eye trackers using off-screen targets , 2000, ETRA.

[11]  Tim Halverson,et al.  Cleaning up systematic error in eye-tracking data by using required fixation locations , 2002, Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc.

[12]  Susana Rubio,et al.  Evaluation of Subjective Mental Workload: A Comparison of SWAT, NASA‐TLX, and Workload Profile Methods , 2004 .

[13]  S. Hart,et al.  Development of NASA-TLX (Task Load Index): Results of Empirical and Theoretical Research , 1988 .

[14]  Poika Isokoski,et al.  Now Dasher! Dash away!: longitudinal study of fast text entry by Eye Gaze , 2008, ETRA.

[15]  Jacob O. Wobbrock,et al.  Measures of Text Entry Performance , 2007 .

[16]  Oleg Spakov,et al.  Fast gaze typing with an adjustable dwell time , 2009, CHI.

[17]  Boris M. Velichkovsky,et al.  Influences of dwell time and cursor control on the performance in gaze driven typing , 2008 .

[18]  Alan F. Blackwell,et al.  Dasher—a data entry interface using continuous gestures and language models , 2000, UIST '00.

[19]  Brad A. Myers,et al.  Analyzing the input stream for character- level errors in unconstrained text entry evaluations , 2006, TCHI.

[20]  Oleg Spakov,et al.  On-line adjustment of dwell time for target selection by gaze , 2004, NordiCHI '04.

[21]  Anke Huckauf,et al.  Alternatives to single character entry and dwell time selection on eye typing , 2010, ETRA.

[22]  Päivi Majaranta,et al.  CHAPTER 9 – Text Entry by Gaze: Utilizing Eye Tracking , 2007 .