interaction media & communication, department of computer science, queen mary university of...
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Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
THE INFLUENCE OF SCREEN READERS ON WEB
COGNITIONTony Stockman & Oussama Metatla Queen Mary, University of London
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
OVERVIEW
• Examine implications of SR technology for web cognition
• Report findings from survey and study of collaborative web use
• Propose draft taxonomy of errors in collaborative web interaction
• Examine potential role of non-speech sound in addressing identified problems
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
FEATURES OF SR WEB INTERACTION
• Default linear model of page presentation• No ambient representation of location on page• No representation of spatial layout• No immediate indication of information density• Little to assist formulation of mental model of
page
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
CURRENT FUNCTIONALITY
• Focus: Jaws, WE and VO.• Cursor key navigation – strength and weakness
of analogy with other apps• Other mechanisms:
• By listing of navigating forward/back between links, headers, frames, tables, forms, text elements, markers etc.
• Forms mode
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
OVERVIEWS
• Important but often under supported/neglected• Typically lists no. of links, frames, headers, and
forms with reminder of related hot keys
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
CURRENT NON-SPEECH SOUND
• Jaws schemes• Window-eyes events• VoiceOver defaults
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
VoiceOver
• Embedded in OS• Factors in switching• Group v. DOM mode navigation• Overview followed by interaction model• Non-speech sound more “visible”
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
IMPLICATIONS FOR COGNITION AND INTERACTION
• Hindered by linear navigation EG pageing through search results
• Hot keys and markers help, but ignore density of info and spatial layout - consequences for collaboration
• Overviews neglect spatial layout, ordering and esthetics,
• Tables are navigable but lack overviews
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
DESCRIBING WEB PAGES
• Employed widely known pages• Characteristics of sighted descriptions:
• Relatively short but covering main features• Column layouts, colours, mood, style, pictures,
emotional response to message
• Characteristics of VI descriptions:• Longer, more factual and granular, more focus on
function and usability • Conclusion: the two groups approach web tasks
from widely differing contexts
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
COLLABORATIVE TASKS
• Involved pairs of sighted and visually impaired users
• Both could read the web pages used• One gave instructions while the other performed
the task• The tasks involved:
• Simple information searches• Comparisons of data values• Navigating pages and filling forms
VISUALLY IMPAIRED INSTRUCTOR
• These tasks were performed generally quite straightforwardly
• VI user was generally familiar with sites• Sighted users perspective generally
compensated for difference in views of each user
• Sources of problems:• Screen-reader’s focus unavailable to sighted user
• Sighted user referring to spatial layout unavailable to screen-reader
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
SIGHTED INSTRUCTOR
• Substantially more problems:• Point in task unclear because screen-reader
focus unavailable to sighted user• Sighted references to spatial layout• CAPTCHEs• Non-standard form controls • Column headers not spoken on forms• Dynamic updating of form fields
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
TOWARDS A TAXONOMY OF COLLABORATIVE ERROR 1
• Location disconnects• Layout disconnects• Missing objects• Navigation disconnects• Contextual disconnects
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
TOWARDS A TAXONOMY 2
• Affordance disconnects• Modal disconnects• Hollistic disconnects• Multi-focus disconnects • Esthetics disconnects
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
NON-SPEECH AUDIO
• Audio is inexpensive and widely used• Screen-readers only gradually adopting limited
non-speech sound, eg forms and progress bars
• Growing body of knowledge on how to design and use (www.ICAD.org)
• Range of techniques that could be examined as part or whole solutions to problems described
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
• Monitoring for dynamic changes• The structure of Earcons could for EG reflect
object type and nature of update• Ambient sound might convey esthetics and/or
interaction mode • Auditory icons might signal affordance
open/closed• Spatial sound might convey overall layout,
density, locations of users
NON-SPEECH AUDIO 1
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
NON-SPEECH AUDIO 2
• Example of non-speech auditory overviews compared with speech, more like a glance
• Spearcons for typical radio button options• Crucial to avoid auditory overload, masking etc.
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc
CONCLUSIONS
• Speech-only model struggles to convey rich web content and enable increasingly complex interactions
• This is highlighted by gap in first impressions of common web pages
• Cross modal web collaboration os subject to a range of disconnects due to differences in presentation and interaction
• Non-speech audio is an under-used mechanism that, with careful design, could help to address some of the issues sited
Interaction Media & Communication, Department of Computer Science, Queen Mary University of Londonhttp://www.dcs.qmul.ac.uk/research/imc