We’ve all been told that alt text is an essential part of web accessibility, but how much detail do we actually need to include and who should do it?
There’s been some discussion over on the DC-Accessibility JISCMail Discussion List (February 2007, “Not Accessible or Adaptable”) about a lot of issues, including whether alt text should always be added to an image. One contributor to the discussion gave a link to a slideshow of dance photographs, where:
“the author refused to label the images with text… his argument being that the photographers images capture and demonstrate an emotional experience, and that whilst text can perform the same expression, he’s not the person to annotate them.”
The photographs in question are various stills from dance rehearsals and performances. There is no accompanying text of any kind, but most people would probably recognise that the people in the photos were involved in some sort of dance medium from the clothes being worn, the environment, and from the positions of the bodies. However, unless one knows the language of dance or the context in which the dance is being performed, the photos may have no further meaning - and could therefore be inaccessible to some people.
This actually brings up several issues:
1. How can one describe an image that expresses emotion or abstract concepts?
2. If such concepts can be described, who should be responsible (and have the capability) for doing so?
3. Where does alt text fit into all this?
1. Describing Emotion and Abstract Concepts
So is it possible to extract emotional and abstract meanings and describe them for people who do not have a concept or understanding of such areas? The Dayton Art Institute Access Art Website has attempted to do so. For each artwork on the Access Art website, there is an image, a section on the artwork in context, comments by the Art Director (including an audio commentary) and a description of the artwork. Each section is no more than a couple of paragraphs. For example, the description of Frishmuth’s “Joy of the Waters” has attempted to put across abstract concepts such as the mood of the statue:
“The girl’s springing, energetic step, joyful expression, and animated hair create an exuberant mood and suggest that she may be a water sprite.” (Marianne Richter, Dayton Art Institute)
This helps make the artwork become more accessible for visually impaired people and for people who do not know the language of art.
2. Responsibility for Describing Images
The people best qualified to describe a visual resource are probably the people who have decided it should be included in the first place. For example, someone with archaeological experience is probably best placed to describe an image of a stone tool, whilst a geography tutor may be the most suitable person to describe a meteorological image from a satellite put onto the university’s VLE (Virtual Learning Environment).
The descriptions used will also differ depending on the image’s intended audience. A museum generally has a wide public audience with many different levels of understanding and access requirements, whilst a Geography department may only have a small number of students at a fairly high level of understanding.
So, unless the photographer in the quote above, is also versed in the language of dance, he is unlikely to be able to describe the dance photos he has taken. Even if he were, he would also need to be aware of the level at which they needed to be pitched in terms of language, description, and audience.
3. Use of alt Text
So where does alt text fit into all this? The W3C (World Wide Web Consortium) WCAG (Web Content Accessibility Guidelines) recommends providing:
“…a text equivalent for every non-text element (e.g., via “alt”, “longdesc”, or in element content)… For complex content (e.g., a chart) where the “alt” text does not provide a complete text equivalent, provide an additional description using, for example, “longdesc” with IMG or FRAME, a link inside an OBJECT element, or a description link.”
Therefore, alt text should be used for every image (even empty alt text should be used for spacers and decorative images), but it should only provide a brief text description of the image - the Guidelines on ALT Texts in IMG Elements recommends no more than 50 characters. Longer descriptions of an image, such as those describing complex images, emotions, or abstract concepts, should not be included as alt text, but should either be attached as a separate link (perhaps using the longdesc or d-link elements) or added next to the image.
Alt text can also be different for different audiences and purposes (see WebAIM’s Communicating the Purpose of the Graphic) and does not necessarily need to be completed by experts. However, although the photos of the dancers should have had alt text, they may well have needed someone with a knowledge of dance to add it. Basic alt text, such as “photo of dance students” could have been added by anyone but would there be any benefit to seeing roughly the same alt text added to over 80 images? A choreographer would be capable of adding more informative alt text, such as stating the dance step or intention, e.g. “photo of a dancer in fifth position”, particularly where the intended audience was other dancers or dance students.
Alt text is a requirement under the WCAG guidelines, but it shouldn’t be used to describe an image in a thousand words - these have to be written elsewhere.