WebSAT Evaluation Rules

WebSAT uses a set of heuristic rules to evaluate the use of tags in web page design. Note: These rules do not form a comprehensive set of guidelines. However, they are a sample set of typical rules to demonstrate the feasibility (and limitations) of an automatic checker. The rules are grouped into six categories as follows (click on a category's link for a more extensive discussion on that category):

Accessibility

It is important that all users, regardless of physical abilities be able to view public websites. Differences in web browsers and hardware capabilities might also limit access for some viewers. WebSAT uses the following rules to test for accessibility:

Include "alternative text" for images, even when not used as links.
Include "alternative text" for images used as links.
Include "alternative text" when using java applets.
Include text anchors or links for image maps.
Include the "noframes" option when using frames.
When specifying colors, use the RGB hexidecimal values. This helps to insure proper color recognition by any browser which does not recognized specified "color names".
Combine the use of BG color and TEXT color attributes. Do not use them alone.

Form Use

If forms are used on a website, care should be taken so that users are able to easily fill in information, erase information, and submit information. WebSAT uses the following rules to test for how forms have been implemented:

The form should include a functionality for returning the completed form.
The form should include a button that is clearly labeled "Send" or "Submit" for delivering responses.
The form should include a functionality for clearing or resetting the form.
The form should include a button that is clearly labeled "Clear" or "Reset" for clearing current information from the form.

Performance

Users are impatient. It is important that they can get to the necessary information in your website quickly. In this section, we check that all has been done to speed up performance so that long delays do not affect the usability of your site. WebSAT uses the following rules to test for performance:

The total amount of graphics should be 30K or less.
Height and width specifications should be given for images.
Images should be in either GIF or JPEG format.
Banner sizes should be in the 468 X 60 pixels range.

Maintainability

Users want timely information and links that really connect to other information. This is not just an issue of maintenance. It is also a design issue. In this section, we check that your site can be easily maintained. WebSAT uses the following rules to test for maintainability:

Relative links should be used when possible.
Head tag information should be given.

Navigation

Most websites do not come with a map. Users have to create their own model of the site as they search for information in that site. It is important that links be descriptive so that users have some idea of what to expect if they follow a given link and how to get back to pages they previously visited. WebSAT uses the following rules to test for navigation:

Each page should contain at least one link.
Links should be displayed in the default browser colors.
Links should be descriptive of what the user will find upon visiting.
Links should not be embedded.
Links should not open a new browser window.

Readability

It is important that users can easily read the important information on your web page without distractions. While graphics and animation add interest, too much of a good thing can quickly become distracting. Information on your web pages should be arranged so that users do not have to scroll many times to see the full text. As with printed text, the density of information is also a consideration in ease of reading. WebSAT uses the following rules to test for readability:

Try to limit the density of the web page.
Limit scrolling text, blinking text,and marquee style text on your web pages.
Do not use horizontal lines across the web page.

Version 2.0
Page last modified: 15 May 2002
National Institute of Standards and Technology (NIST)