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Low vision interaccion2018v4

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Lourdes Moreno, Xabier Valencia, J. Eduardo Pérez, and Myriam Arrue. 2018. Exploring the Web navigation strategies of people with low vision. In Proceedings of the XIX International Conference on Human Computer Interaction (Interacción 2018). ACM, New York, NY, USA, Article 13, 8 pages

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Low vision interaccion2018v4

  1. 1. Exploring the Web navigation strategies of people with low vision Lourdes Moreno (lmoreno@inf.uc3m.es) Computer Science Department Universidad Carlos III de Madrid Xabier Valencia, J. Eduardo Pérez, Myriam Arrue EGOKITUZ: Laboratory of HCI for Special Needs University of the Basque Country (UPV/EHU) September 12–14, 2018, Palma, Spain
  2. 2. •Lourdes Moreno, Xabier Valencia, J. Eduardo Pérez, and Myriam Arrue. 2018. Exploring the Web navigation strategies of people with low vision. In Proceedings of the XIX International Conference on Human Computer Interaction (Interacción 2018). ACM, New York, NY, USA, Article 13, 8 pages. DOI: https://doi.org/10.1145/3233824.3233845 •https://dl.acm.org/citation.cfm?id=3233845 • Interacción 2018, September 12–14, 2018, Palma, Spain
  3. 3. INTRODUCTION Scope • “Low vision” refers to visual impairments other than blindness • Impairments that cannot be corrected with regular glasses, contact lenses, medicine, or surgery • Visual Impairments • Visual Acuity • Light Sensitivity • Contrast Sensitivity • Field of Vision • Colour Vision • Functional Vision Interacción 2018, September 12–14, 2018, Palma, Spain
  4. 4. INTRODUCTION Incidence •There are 246 million people worldwide who have low vision •Increase: aging population Interacción 2018, September 12–14, 2018, Palma, Spain
  5. 5. INTRODUCTION Accessibility Barriers •People with low vision experience accessibility barriers when they interact with the web • Small font sizes • Font colours that make reading even more difficult • Background images on web pages that decrease legibility Interacción 2018, September 12–14, 2018, Palma, Spain
  6. 6. INTRODUCTION Assistive Technologies (AT) •In order to access the web, people with low vision employ assistive technologies • Screen magnifiers: magnification, colour inversion, cursor enhancement features • Digital magnifying glass • Screen readers: transform web content into auditory output •Web browser zooming tools Interacción 2018, September 12–14, 2018, Palma, Spain
  7. 7. INTRODUCTION Motivation • Incidence • Regulatory framework • Accessibility barriers • The majority of the research has been oriented towards total blindness rather than low vision => Opportunities exist for improving low vision accessibility Interacción 2018, September 12–14, 2018, Palma, Spain
  8. 8. OBJECTIVE •To explore the navigation strategies of low vision users in order to select the appropriate accessibility techniques to employ in the designing of web interfaces for this group • Literature review • Exploratory study Interacción 2018, September 12–14, 2018, Palma, Spain
  9. 9. LITERATURE REVIEW •More focused on blind users or people with visual disabilities, without distinguishing between the specific needs of blind and low vision users Interacción 2018, September 12–14, 2018, Palma, Spain •Low Vision works: • Accessibility guidelines: basic transformations • Font size, font family, font colour, letter spacing, hyperlink colours • A personalized user interface approach: one single method of adapting the presentation may not be sufficient due to the heterogeneity of the group.
  10. 10. LITERATURE REVIEW •Accessibility standard: Web Content Accessibility Guidelines (WCAG) • Referenced in the regulatory compliance frameworks (Section 508, EN 301 549, WCAG) Interacción 2018, September 12–14, 2018, Palma, Spain •WCAG 2.0 has deficiencies and fails to meet web accessibility requirements for people with low vision • Low Vision Accessibility Task Force (LVTF) => Accessibility Requirements for People with Low Vision • (new recommendation) WCAG 2.1
  11. 11. LITERATURE REVIEW • Navigation strategies differ for visually impaired users according to the AT used • Interaction with the magnification software: • Partial view of the page (loss of context) • Horizontal scrolling Þ Users are required to move their field of vision frequently (numerous gestures) • Some works question the support capacity of assistive technology Interacción 2018, September 12–14, 2018, Palma, Spain
  12. 12. LITERATURE REVIEW •Alternative assistive technologies other than the traditional ones used to improve accessibility for people with low vision • Multi-modal user interfaces • Conceptual approaches for making web pages accessible • A browser that allows parameters to be adjusted in order to maximize reading efficiency Interacción 2018, September 12–14, 2018, Palma, Spain
  13. 13. EXPLORATORY STUDY Participants •Six participants from the Spanish Association of People with Low Vision •Experimental sessions (UC3M, Servimedia) •Observational methods •Participants’ interactions were recorded with a camera located behind them during experimental sessions. Interacción 2018, September 12–14, 2018, Palma, Spain ID Gender Age Assistive Technology Web Expertise U1 M 44 ZoomText 9.1 High U2 F 54 Browser Zoom High U3 F 52 ZoomText 10 + Text Reader + Browser Zoom High U4 F 65 Browser Zoom Medium U5 M 45 ZoomText 10 + Browser Zoom High U6 F 41 Browser Zoom High
  14. 14. EXPLORATORY STUDY Stimuli •Discapnet website • WCAG • The Barrier Walkthrough Method revealed some accessibility barriers for people with low vision • Insufficient visual contrast • Lines of text that are too long • Inflexible page layout • Failure to implement skip links • …… Interacción 2018, September 12–14, 2018, Palma, Spain
  15. 15. EXPLORATORY STUDY Procedure •Inform participants of the purpose of the experiment •Sign a consent form •Search tasks on the website without using a search engine or any other similar facilitator •The target page was three links away from the homepage •Time for performing the task was limited to ten minutes. Interacción 2018, September 12–14, 2018, Palma, Spain
  16. 16. EXPLORATORY STUDY Information analyzed •Task completion time •Total number of pages visited •Number of pages revisited during the task •Lostness formula •Number of zoom magnify operations •Number of zoom de-magnify operations •Number of vertical page scrolling actions •Number of horizontal page scrolling actions Interacción 2018, September 12–14, 2018, Palma, Spain
  17. 17. EXPLORATORY STUDY Results • The navigation bar component is the most explored element, used by participants as a reference point. • Scrolling actions • Vertical scrolling does not present any difficulties (mouse wheel) • Horizontal scrolling requires a more complex sequence of actions and causes loss of context • Moving the field of vision to the bottom of the page • Clicking • Dragging the scroll bar • Going back to the content • Horizontal scrolling occurred depending on the magnification applied to the webpage Interacción 2018, September 12–14, 2018, Palma, Spain
  18. 18. EXPLORATORY STUDY Results • Some participants accessed the web page that contained the target link but did not locate it. • The link was visible on the screen • However, participants were focused on the main content of the webpage at the centre of the screen while the link was out of their sight on the left side of the screen • Multiple columns are problematic • Certain factors such as small font sizes, contrast with font and background colours decreased legibility Interacción 2018, September 12–14, 2018, Palma, Spain
  19. 19. EXPLORATORY STUDY Results •Magnification levels Interacción 2018, September 12–14, 2018, Palma, Spain
  20. 20. EXPLORATORY STUDY Results • Magnification actions were performed before the following actions: • Exploring vertical/horizontal navigation bars • Clicking on a link located on the vertical navigation bar • Using the vertical scroll bar • Demagnification actions were performed before the following actions: • Exploring the content • Clicking on the browser’s back button • Exploring the horizontal navigation bar • Clicking on a link located on the horizontal navigation bar • Using the horizontal scrollbar (“ctrl” key together with the mouse wheel) Interacción 2018, September 12–14, 2018, Palma, Spain
  21. 21. EXPLORATORY STUDY Discussion • Including the navigation bar component near the top of the page • Minimizing the magnification / demagnification operations: • Presenting important information with a large font size • Organizing text in small blocks • Presenting important information close to the centre of the screen • Adding a visible hot area around links • Using presentation properties that distinguish the links • With regard to avoiding the horizontal scroll: • Linearize the page • Responsive design Interacción 2018, September 12–14, 2018, Palma, Spain
  22. 22. CONCLUSIONS • People with low vision experience accessibility barriers when they interact with the web, despite using their assistive technology • In order to discover the navigation strategies used by people with low vision to avoid accessibility barriers we carried out: • A review of the corresponding literature • An exploratory study with six users with low vision • Solution: web user interface approaches based on adaptation techniques to provide a better web navigation experience corresponding to specific individual user needs, such as the type of assistive technology used Interacción 2018, September 12–14, 2018, Palma, Spain
  23. 23. WORK IN PROGRESS •Proposal of the adaptation techniques combining techniques obtained in this study with others proposed in the literature •Automated transcoding system • An adapted web interface for people with low vision is generated from a web interface. •An experimental study with users with low vision to validate the approach Interacción 2018, September 12–14, 2018, Palma, Spain
  24. 24. Exploring the Web navigation strategies of people with low vision Lourdes Moreno Information Technology Department Carlos III University of Madrid Xabier Valencia, J. Eduardo Pérez, Myriam Arrue EGOKITUZ: Laboratory of HCI for Special Needs University of the Basque Country (UPV/EHU) September 12–14, 2018, Palma, Spain

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