Accessibility

Jun.-Prof. Dr. Mark Hall

Sommersemester 2019

Themen

  • Barrierefreiheit
  • Barrieren
  • Rechtliche Aspekte
  • Testen

Barrierefreiheit

Barrieren

  • Vollständige Blindheit
  • Teilweise Sehbeschränkungen
    • Tunnel / Peripheriesicht
    • Verschwommene Sicht
    • Farbblindheit
  • Auditive Beschränkungen
  • Motorische Störungen
  • Mentale Störungen
  • Alter

Warum Barrierefreiheit?

Für mehr Benutzer

Weil Accessibility für 10% der User unerlässlich ist

Weil Accessibility für 30% der User hilfreich ist

Weil Accessibility für 100% der User Verbesserungen bringt

Beispiel Web

  • Perceivable
  • Operable
  • Understandable
  • Robust

Beispiel Web

<main id="content" class="root-index" role="main">
  <form action="/search" method="get" role="search">
    <label>Password
      <input type="password" aria-describedby="passwordHelpText">
    </label>
    <p class="help-text" id="passwordHelpText">Your password must
      have at least 10 characters, a number, and an Emoji.</p>

  </form>
</main>

Beispiel Android

  • Label UI elements
  • Group content
  • Create easy-to-follow navigation
  • Make touch targets large
  • Provide adequate colour contrast
  • Use cues other than colour
  • Present accessible media content

Warum ist Accessibility so schlecht?

To implement this technique, first determine what functionality is available to users on the page. In this step, it is important to consider functions performed using both the mouse and the keyboard together. Examples of functionality include the use of physical controls such as links, menus, buttons, checkboxes, radio buttons and form fields as well as the use of features like drag and drop, selecting text, resizing regions or bringing up context menus. Other examples of functionality may based on tasks such as adding or removing an item from a shopping cart or initiating a chat session with a sales representative.

Once the functionality of the content has been determined, the author verifies that each of the functions identified can be performed using only the keyboard.

Alle Funktionen müssen über das Keyboard bedienbar sein.

"Der Kontrast dieses Elements ist 4.47, sollte aber mindestens 4.5 sein"

Wie kann man modernes Testen auf Accesibility ummünzen?

Literatur

  • Tullis, T. and Albert, B. (2013). Measuring the User Experience. Morgan Kaufmann.
  • Krug, S. (2014). Don't Make Me Think Revisited. New Riders.

Übungsaufgabe