Section 2.1: Defining Accessible Images, Part 2
Types and roles of images
The images on Web sites can be used for multiple purposes. The purpose of an image needs to be considered in the development of text alternatives.
Images can serve in the following roles:
- To convey information (such as a stop sign showing the word STOP)
- An image of text
- An image that supplements content on the page, such as a diagram or photograph illustrating a point
- An image that is the content of the page, such as a map, architectural drawing, or work of art
- An image displayed as a response to user action, such as an exclamation point that signals an error in a form
- An image to test that you are a human being and ot a spam robot—for example, a distorted word that must be typed in to a form to continue
- To provide a link to another page, activate a change on the current page, or submit a form
- Only to make the page visually attractive
- An image that is not especially important to understanding the content of the page or site
- An image used only to control formatting or not intended for presentation to the user
Activity 1: Identifying the purpose of an image
Question 1
The Harry Ransom Center 
has the following home page (screenshot below). To learn more about Arnold Newman's photographs, a user would click on the black and white image in the center of the screen.
The image conveys information and is a link to another page. The image is informative because it not only provides examples of Arnold Newman's work but informs the user that the Ransom Center acquired his archives. It is also a link that will take the user to the page of Arnold Newman's work. The image could be considered decorative for the page but could not be considered decorative only because users will miss important information if they do not know about the content or function of the image.
Question 2
The Harry Ransom Center Collections Page (screenshot below) allows a visitor to select a collection to browse.
In this case the image could be from 2 perspectives and basically is the choice of the Web site developers. The image could be interpreted as conveying information because this is a site about various works of art, and the photograph is an example of the art work in the Ransom collection.
However, a case could be made that the image is decorative only because to understand and navigate this page, it is not important that a user know that a photograph of Ingrid Bergman is on the page.
Questions 3-5
This page from the New York Historical Society (screenshot below) has 3 images of the Harry Howard statue. None of these images allow the user to move to another page but the smallest image allows users alternate views of the image.
In this case the largest image serves as a decorative only image because it most of the image has been grayed out and serves as a background for the main text.
The medium size image (#2) offers uses a full view (although small) of the statue. This page is about this statue so the medium size image conveys information.
The smallest image allows the user to go back to the full view of the statue after they have viewed the close-up images. This page is an example of how the same image could need different text alternatives based on the purpose of the image.
