Eye – tracking in usability testing and gazeinteraction

Haakon Lund
Royal School of Library and Information ScienceCopenhagen
Denmark

Remote systems / Mobile systems

Price: 10.000 US $ - 40.000
US $Technology

Near infra red (NIR) light is reflected in corona and / or iris
Binocular

The eyeFovea

Usability studies

Eye tracking and usability

Web usability
Jacob Nielsen (Large scale experiment 250 + test subjects)
Poynter Institute (Web news paper reading)
Text reading
Computer games
Software (user interface design)
Physical space
Car driving
Interior designWhat captures our attention?

Attention creating objects

Concepts in eye tracking

Peripheral view
Saccadic eye motion
The image of an observed object is resolved by fovea
Re-orientation of the eye between fixations
Reduced vision during saccades
Fixation
Observing object ( - so we remeber!)
40 – 600 ms (avr. 200 – 300 ms)
Fixation filtering
fixation time / fixation radiusFixation / saccades

What does it tell us
Fixation lenght
Cognitive load
Number of fixations
ImportanceOrder of fixationsorganisation

Gaze plot

Heat-map (F – Pattern reading web pages)

Tobii eye tracker and Clear View

High quality tracker
Head movements
Error rate measured
gazepont/ Intended
gazepoint = 0,5 cm
Sampling rate 50 Hz,Latency 25 – 35 ms
Clear View for dataanalysis

Eye tracking and usability studie

Supplement
Data analysis
Setup
Task definition
Test
RTA (interview)

Danish Statistical Bureau

Test of certain design elements and access to database
10 user tasks
Retrospective think aloudTask example
Question to subject:
Find the page describing a given political reform.
Print the page
Purpose:We would like to know if the user see’s the print icon in the top right corner.
History:According to web design guide lines the user should be given the possibility for
printing the web page in a print friendly layout. Our expectation is that the user do not
see the icon but uses the print possibility build into the browser.

Text reading

Simplification of language = faster reading and improved
understanding
Number of fixations and order
Reading time(Control questions)Original bureaucratic text

Re-written text

Results

Antal fixationer

T idsforbrug

800

180000700

160000140000120000500
Bearbejdede

400

Ubearbejdede300

TidFixationer

600

100000Bearbejdede

80000

Ubearbejdede

60000

20040000

10020000
0012
Person12Pe rson

Gaze Interaction
Birger Bergmann Jeppesen

1996 Diagnosed with ALS / MND
1998 Loss of muscle movement
Before he did loose his muscle control
he went for a world travel.
Birger is living in is home and isprovided with caretakers 24/7/365.
Yearly contribution from healthauthorities approx. 300.000 US$
Birger is very active and he is theauthor of a book about his life with ALS
and several DVD’s.
Birgers quality of life depends on being
able to communicate.

ALS – Birger Bergmann Jeppesen”Birger’s quality of life depends on him to be able tocommunicate. I really hope his Birger keeps his ability tocommunicate. If it was taken away from him I know his qualityof life would be reduced considerably”

Arne Lykke Larsen

Diagnosed with ALS in 2000 at 35
Loss of muscle control 2002
Active GazeTalk user since 2002
Using GazeTalk for preparing his lectures at Odense
University where he is working as professor in highenergy physics.
Arne uses GazeTalk for writing both danish andenglish.
He is now using a Quick Glance eye tracker at home
and a Tobii system MyTobii P10 at work.
He has been using a BrainFinger EMG – switch for 6
month with GazeTalk.

Film with Birger

How to communicate when you only can moveyour eyes?

Numbers of ALS Patientsin ALS/MND Alliance Countries and Regions

NorthEurope

Asia

Country, Total No.
No. onNo. in NotesRegion
Respirator TLS
Canada3,000
150
Mexico
1,040
310U.S.
30,000Cyprus40
50
Denmark
450
2520
Germany
3,500
Iceland
20Israel
600
Italy
5,000
Norway200
170 Non Member
Scotland
278
153U.K.
4,000400Japan
7,0002,100
70Korea
1,500-2,0001200Singapore
10- Non Member
Taiwan250
6925

The investigation was done by e-mail. The numbers are not accurate.

Advantages of Gaze Communication

Relative fast typing + 10wpm
Easy to learn from zero to 2.5 hours
No muscle strain – several working hours possible
Can be used at late stages of ALS/MND
May give access to a range of PC applications
Very active research and production development in domain

Communication speeds

Speech150–250 wpm

Traditional typewriting

65 wpmStylus tapping on screen keyboard

9–30 wpm

Cursive handwriting

30 wpmMorse code

25–30 wpm

Reading

200 - 400 wpm

Mobile phone: Multi Tap8 wpm

Mobile phone: T920 wpm

Various AAC systems

2–8 wpm

Gaze typing with full on-screen keyboard

7 wpm

Gaze typing with large button keyboard

10 wpmGaze writing with Dasher

25 wpmDis – advantages of Gaze Communication

Expensive hardware
Not possible to select small objects
Sensitive to sunlight or other light sources
Problem with vision correction means
Bi-focal glasses
Hard lenses
Physical limitations
May take to much time to masterEffectiveness requirements for gaze communication
systemRow – column manual scanningHigh availability
Instant operation
RobustMobile
Affordable
Usable at all stages of ALS/MND
Easy to learn

Stages of ALS/MND that gaze communication can support

Loss of voice
Deterioration of leg / arm movement
Limited movement of head / hand
Only eye movement / facialmuscle control
No eye – movement (locked – in) EMG
Hitachi ”Kokoro Gatari”
Brain Finger

GazeTalk

Communication software
On – screen key board
limited numbers of keys
Write
Type – to – talkPrediction
Characters and words
Smooth reading PDF files
Multimedia support
Movies – MusicWeb – browser
Front end to full text database
Archive of Danish literature
Multi lingual
Developed in cooperation with 4 people with ALS

Gazetalk – video demo

gazetalk_jp_final.mov

Library access (OPAC)

Access to database’s (Library indexes or Full-text journals)
Studies shows that even if database hosts follow accessibility
standards for interface design the actual interface may not be
usableOne host = one interface
People with little muscle control (locked-in syndrome)
Late stage Amyotrophic Lateral Sclerosis (ALS/MND)
Spinal core injuriesAlternative input devices

Interfaces

Technologies available

Low tech
Human assistanceIntrusiveSlow
High techGaze interaction
Facial EMG-switch (Brainfingers)
AutonomyfasterProject

Scope:
To design and test a generic interface for access to library resources
In collaboration with the Royal Library in Copenhagen
Archive of Danish Litterature (ADL)Size
70 authors
App. 17000 works (books, poems etc.)
Text available in xml partially according to TEI-DTD (Text Encoding
Initiative Document Type Definition)<pb> (page break used for page numbers!!)
No MARC – records
Page by page storageAccessLibrary specific standards available
Federated search
SRW based on Z39.50
Retrieval of bibliographic records not full text
Not supported by e-journals
A solution?
Web-service technology
SOAP – WDSL (REST) – XML –XSL(T)Web-service“A web service is a software system designed to support interoperable machine-tomachine interaction over a network. It has an interface described in a machineprocessable format (Specifically WSDL). Other systems interact with the Web service
in a manner prescribed by its description using SOAP-messages, typically conveyedusing HTTP with an XML serialization in conjunction with other Web-relatedstandards” (W3C, 2003)
Used byGoogleAmazon
Weather forecast services

Web-service+Control of user interface design
One client – one design – many hosts
Adaptable
Tailord to the individual user
Standardized
Data intensive
Standardized

Web-service

ServerClientinterface

WSDL

GetAuthorList[arg1, arg2][Author list]XSLTXML