Accessibility issues: Images and the use of ALT Text
Screen reader users, such as the visually impaired, rely upon ALT text for a
textual representation of an image that they may not be able to see. If the
image adds value or meaning to the resource adding ALT text enables a screen
reader user to interact with the resource in the same way as everyone else
An image without ALT text
Image with ALT text
(Screen reader may announce
picture or ignore image without
ALT text)
(Screen reader reads ALT
text)
Click for slide read by screen reader JAWS
Note: The eLearning Team banner is an image with ALT text.
This gets read out by JAWS. The footer image does not have ALT
text associated with it.
Accessibility issues – How to add ALT text
In MS Word and PowerPoint (2010)
• Right click on image (it may require 2 right clicks)
• Select: Format Picture
• Select: Alt text
• Type alternative text into
the ‘Description’ box
For detailed instructions for all versions of MS Word see:
http://webaim.org/techniques/word/#provide2007
Accessibility issues – How to add ALT text in MyAberdeen
In MyAberdeen, using the content editor:
Add Alt Text to the Image
Description box that appears
when adding an image
Leave the Title box empty
For further advice contact elearning@abdn.ac.uk
Accessibility issues – Appropriate ALT Text
In cases where an image adds no value to a learning resource, and is included
merely for visual effect, good etiquette requires an author to insert “” (double
parenthesis) in the Alt text field (apart from in PowerPoint where doing this is
counterproductive and the ALT text field should be left blank) . If the ALT text
field is left blank most screen readers will announce “picture” and the user
will be left wondering whether or not the image was important. On detecting
“” most screen readers will skip past the item (apart from in PowerPoint
where the screen reader would read double parenthesis...)
Advice on the appropriate use of ALT text can be found at
http://webaim.org/techniques/alttext/
Accessibility issues – ALT text and Images
Links :
University of Aberdeen’s eLearning Team accessibility guide:
http://www.abdn.ac.uk/eLearning/accessibility/checklist/alt-text/
Alternative Text in context: http://webaim.org/techniques/alttext/
WebAim’s Microsft Word Accessibility article (including the use of ALT text):
http://webaim.org/techniques/word/#provide2007
Creating accessible PowerPoint files:
http://webaim.org/techniques/powerpoint/
Add alternative text to a shape, picture, chart, table etc in MS Office:
http://office.microsoft.com/en-us/support/add-alternative-text-to-a-shapepicture-chart-table-smartart-graphic-or-other-object-HA010354748.aspx?CTT=1