1. Twenty Years of Eye Typing: Systems and Design Issues
Tampere Unit for Computer Human Interaction
Päivi Majaranta & Kari-Jouko Räihä
25 March 2002
ETRA2002

2. Contents Introduction Typing by gaze Keyboard layout
Focus
Feedback
Selection
Keyboard layout
Customization and context of use
Typing vs. communication
System level issues
Discussion 1

3. Introduction
Eye Typing means producing text by using the point of gaze
Needed by people with severe disabilities
Control of the eyes may be the only option
Need for a communication system is acute
Focus on producing text
But: considerations of communication strongly present, since most of the systems are designed for use as communication systems 2

4. Typing by gaze A typical eye typing system has
an on-screen keyboard
an eye tracking device to record eye movements
a computer to analyze gaze behavior
To type by gaze the user
focuses on the letter s/he wants to type
gets feedback by the system (e.g. highlight)
selects the item in focus (e.g. by a switch)
QuickGlance 3

5. Focus Move focus by looking at the wanted item
Mouse emulation
moving the cursor by moving eyes (& head)
Dwell time
continuous fixations on an item (< 1 s)
Shift focus by short gaze glances
eyes as switches
needed if difficulties with fixating
EPCOS, Frietman and Kate 1978
Shein, 1997 4

6. Feedback Currently focused item Cues for dwell time duration
Successful selection
Visual
highlighting, changing colors
moving, animated, shrinking cursors
Auditory
beep, click
spoken (letters, words, sentences)
Proper is feedback especially important for disabled
who may have never controlled much anything
EagleEyes, Gips and Olivieri 1993
ERICA, Lankford, ETRA2000 5

7. Selection Focusing and selecting may be linked Dwell time
May not be perceived as separate operations
Dwell time
Item is focused and subsequently selected
May be interrupted by looking away before the time runs out
Blinks, winks, wrinkles
Must be separated from natural blinks
Additional switches
Also, eyes as switches (with scanning)
Off-screen targets
VisionKey, Khan et al 6

8. Keyboard layout QWERTY not always best Items must be large enough
Alphabetic may be faster to learn
Most common letters may be grouped together
Items must be large enough
 Not much space left for text and other items
Accuracy depends on eye tracking device, screen resolution, distance from the user
The bigger the better up to ~4 degrees
Items can be grouped to selection menus
T9, probabilistic character layout
EagleEyes, Gips & Olivieri 1996
This is the text f_
A to Z
Delete O I A
6 most
likely
words U R L
Space
Type-To-Talk, Hansen et al., 2001 7

9. Customization and context of use
The skills and needs of the users vary a lot
Customizable features
Dwell time duration
Keyboard layout
size, color, location, content, …
Cursor appearance and functioning
Sound (on/off, volume, earcons, speech)
Possibility to disengage eye-control
Integration to other applications
Control Windows/Macintosh
zooming, screen magnifiers, fish-eye views
QuickGlance EyeCons, Rasmusson, CSUN99 8

10. Typing vs. communication
Eye typing is slow
Only one or a few words per minute
Hard to have a conversation!
Methods to speed up eye typing
Phrases for everyday usage
Sentence buffers “please give me” + “water”
Character & Word prediction
Dictionaries and predefined grammars
New methods, like Dasher
 up to wpm
Communicative icons
Not all can (learn to) read and write!
LC Eyegaze, Chapman 1991
Salvucci, 1999 9

11. VisionKey, http://www.eyecan.ca
System level issues
Virtual keyboards and communication aids
No need to redo well-done work
Many features already implemented
“sticky keys”, word prediction, customization
environmental control, integrated speech
Portability
Possibility to attach a wheelchair
Size
Sensitivity to body movements
Changing lighting conditions
EagleEyes,
VisionKey, 10

12. Eye Communication Systems
BlinkWriter, Murphy et al., 1993,
EagleEyes, Gips et al., 1993, Boston College, MA
EPCOS & EYE-SISTANT, Frietman et al., 1984, TU-Delft, Holland
ERICA, Hutchinson et al., 1987, Univ. Virginia
EYECOM, Rosen and Durfee, 1987
EYE-gaze, Tokorozawa, Japan
Eye-Switch Controlled Communication Aids, Kate et al., 1979, TU-Delft, Holland
EyeScan, Eulenberg et al., 1985
EyeTyper, Friedman et al., 1981
EyeWriter, Wiesspeiner et al., 1999, Graz, Austria
LC EyeGaze, Chapman et al., 1991, LC Technologies, Virginia
Quick Glance, Rasmusson et al., 1999
SiVHa, Blanco et al., 1998, Univ. Navarra, Spain
Type-To-Talk, Hansen et al., 2001, IT-University Copenhagen, Denmark
Viserg Eye Mouse, Istance et al., 1993, Univ. Leicester, UK
VisionKey, Kahn et al., 1995, Ottawa Ontario, Canada
VISIOBOARD, EU/Telematics project, 2000 … 11

13. Discussion Further development still needed
Typing issues not been studied in detail
methods for editing text
selecting a chunk of text
scrolling text
fast undo methods
improving typing rate
interaction between virtual keyboard and text field
usefulness of various forms of feedback, ...
How to start up (re)calibration?
Eye typing provides a rich set of issues for study
from practical point of view: to develop more usable systems
from research point of view: to understand gaze communication task 12

14. Thank you for your attention!
Questions?
PS. From our web page you will find an updated
list of eye typing systems, links to their homepages, extra info, etc. 13