Accessibility zWeb should be usable by everyone This includes users with: zVision impairments...
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Transcript of Accessibility zWeb should be usable by everyone This includes users with: zVision impairments...
Accessibility
Web should be usable by everyone
This includes users with:Vision impairmentsHearing impairmentsMobility impairments
Statistics
8 million people with visual impairments
20 million deaf or hard-of hearing250,000 with spinal cord injuries500,000 with cerebral palsy330,000 with MSMore that half US population over 65
has some type of impairment
Issues involving Vision
Web very visually oriented Significant challengesSeverity ranges from total blindness
to low visionColor blindness Visual Stimuli
Information Delivery
Information display on traditional monitor not available to users with visual impairments
Two assistive technologies:Screen ReadersRefreshable Braille displays
Screen readers
Reads text component of web screenIncludes:LinksMenusDialog BoxesError Messages
Screen Readers
Several vendors offer screen readersPrices range from $300 to $1000Page must be reformatted to support
screen readersHTML “lang” attribute controls
language page will be read in
Refreshable Braille Display
For people who are deaf as well as blind screen readers do not work.
Translates text of page into BrailleSingle line of Braille textPrices range from $4500 to $14,500
Grade II Braille
Refreshable Braille Display
Reformatting Text
For screen readers to work text of page must be formatted to support linear delivery
Tabular dataLabel for ElementsSkip navigationAlt Tags for images
Tabular Data
Course Time Day Prerequisite Instructor
211 11:30 pm -1:00 pm MW None McDonald
211 10:30am - 12:00 pm TR None Luecking
212 5:45 pm - 9:00 pm M 211 Carter
212 11:30 pm - 1:00pm TR 211 Chan
Markup Strategy for Tables<table border="1"> <thead> <tr>
<th id="c1"> Course </th><th id="c2"> Time </th><th id="c3"> Day </th><th id="c4"> Prerequisiste </th><th id="c5"> Instructor </th>
<tr></thead><tbody><tr>
<td headers="c1">211</td><td headers="c2"> 11:30 pm -1:00 pm</td><td headers="c3">MW</td><td headers="c4">None</td><td headers="c5">McDonald</td>
</tr><tr>
<td headers="c1">211</td><td headers="c2"> 10:30am - 12:00 pm</td><td headers="c3">TR</td><td headers="c4">None</td><td headers="c5">Luecking</td>
</tr>
<tr> <td headers="c1">212</td> <td headers="c2">5:45 pm - 9:00 pm</td> <td headers="c3">M</td> <td headers="c4">211</td> <td headers="c5">Carter</td></tr>
<tr> <td headers="c1">212</td> <td headers="c2">11:30 pm - 1:00pm</td> <td headers="c3">TR</td> <td headers="c4">211</td> <td headers="c5">Chan</td></tr></tbody></table>
Label Elements of Forms
<form action="Billing Info" method="post"><fieldset> <legend class-"TitleLarge"><b>Billing Information</b></legend><p><label for="firstname">First name (required):</label><input id="firstname" type="text" tabindex="1"></p><p><label for="lastname">Last name(required): </label><input id="lastname" type="text" tabindex="2"></p></fieldset>
</form>
Skip Navigation
Normal Page
Alt Tags(None)
Alt Tags (Descriptive)
Other Vision Issues
Screen MagnifiersColor Blindness:
8% male population 0.5% Female population Most common red/green
Photo Sensitive Epilepsy
Color Blindness
This is an Ishihara plate commonly used to check for red/green color blindness
Color Blindness
This is what a red/green color-blind person might see. Note that the digit (3) is practically invisible.
Mobility Impairments
Conditions with affect use of keyboard and mouse
Might be difficult, Might be impossible
Predictive typingSpeech recognitionAlternative input technology
Hearing Impairments
Few more issues:Captioned mediaOpen or Closed captioningAmerican Sign Language
Web Accessibility Initiative
Promote usability for people with disabilities
Goal of Universal AccessSet of guidelines which address 2
themes: Graceful Translation Make content understandable and
navigable
Web Accessibility Initiative Guidelines
Globalization
Web is growing all over worldNumber of Non English speaking
users rapidly increasingUsability issues involve use of
language and cultureThis processes is called globalization
Global User Population
Internationalization
Internationalization single design used world wide
Simpler textUnambiguous display of number,
currency, dates, and timesIsolate and remove culturally specific
language
Localization
Added cultural contextTranslation of web page into local
languageRelevant content
Text and Translation
Translation: human or automatic?Attention to writing styleExpression of dates, timesExpress currency in local termsLabel units of measurements
Languages Can Expand Labels
Page Layout
Unicode for character supportColor issuesIcon issues (including flags)Text Alignment (left vs. right)
International User Testing
International and local sites need user testing
More involved than traditionalTest success of translationInternational Inspection as
alternativeDifficulties dues to language gap
Personalization
Strategy for gaining competitive advantage
Added service for a userSpeeds task completion (I-Click)Can require loginCookiesDynamic
Privacy Concerns
No right to privacy in USPrivacy ContractsRequest of personal information can
cause users to leave siteHighly related to trust
Trust
Many factors affect trust:ContextPerceived SimilarityStanding in organizationBehaviorCertificationReferences
Fostering Trust
Help establish credibilitySecurity StatementSafe display of personal informationUse of secure serversConfirmation of all costsConfirmation of shipping address
Controlling Privacy
No standard for enforcing privacy in place
P3P standard developedEnforces and exposes site’s privacy
policyTools to inform users of compliance
with their selected privacy policy
Trust (P3P)
Trust (P3P)
Privacy Bird
Privacy Bird
Shows Embedded Content
Privacy Bird