Review of CommonLook™ Section 508 Plug-In for Adobe Acrobat

Strengths:

• The plug-in helps evaluate a PDF document for accessibility and Section 508 compliance in a systematic, standards-based approach.
• The tool follows Section 508 standards, which is a common accessibility standard used in many US government and non-government organizations.
• CommonLook does not claim to be a fully automated evaluation and repair tool. It automates as much of the evaluation process as possible, but acknowledges that some elements must be evaluated by a person.
• Several tasks that are usually quite tedious in Acrobat are mush easier using this plug-in. The two best examples of this are adding text descriptions to images and adding headers to data tables.

Weaknesses:

• The learning curve with this tool can be quite steep and some tasks are more complex than they need to be.
• The user guide is overly detailed and might be hard to locate. Because of the complexity of the tool, a clear user guide would be extremely valuable.
• The price might make it an unrealistic solution for groups with limited funding, or groups who do not work with PDF files on a regular basis.
• Because the tool focuses specifically on Section 508 standards, an organization following other standards or guidelines may have a difficult time using the tool to fit their needs.
• This plug-in is only supported on Windows 2000 or XP.

Alt text for images

If you run the standard evaluation (Plug-Ins > CommonLook > Section 508… > OK), the first thing CommonLook will check for is text equivalents of any images. This is an area where this tool really shines.

CommonLook will open a window with two panels, one on top of the other. In the bottom panel, you will see one page of the PDF document you are evaluating. In the top panel you will see a table with one row for each image in the page. The panels would be easier to work in if they could be positioned side-by-side as well, but it functions fine as is.

When you click on a row in the top window it should highlight an image in the bottom window. You then have the option of adding or editing appropriate alt text. You might notice that there are two columns in this table that apparently serve the same purpose, Actual Text and Alt Text. That is because there are two types of alt text in PDF:

• Actual Text should be used when the graphic is an image that is composed of text and should be read as text. An example might be a heading that has a gradient or shadow applied to it.
• Alt Text is an alternative equivalent for non-text graphics.

You will need to select the "Pass" radio button for each image before proceeding.

This process is well implemented for a couple of reasons:

1. Adding alt text to images can be a tedious process in Adobe Acrobat Pro (although much less tedious in version 7) and this tool makes the process much easier.
2. NetCentric does not "pass" a PDF when all of the Figure tags have alt text present. Instead, it requires you to look at each image and either add appropriate alt text or confirm that existing alt text is indeed appropriate.

Color contrast

A grayscale version of the PDF will appear. You can then manually determine if there are any problems with color contrast.

Reading order

The visual order of a PDF can sometimes be very different from the reading order, and correcting the reading order of a PDF can be a difficult and time consuming process. CommonLook has a tool called the Logical Structure Editor which can help you compare the visual order of the PDF with the reading order of containers and tags within the file. Within the interface you can also tags and reorder elements. The Logical Structure Editor can also be used to tag and associate text descriptions to forms.

Depending on the complexity of your file, this can be a fairly straightforward step or a very difficult one. It may be helpful to enable all of the visual cues available in the tags panel. This can be done by selecting View from the menu and then checking Borders and Glyphs. The window should then look something like this:

Although this is a very powerful tool, the amount of information presented may be overwhelming. If repairing a large number of files, consider scaling back or using this tool as the last step of the evaluation. Many of the changes you make to the document while fixing other elements, especially tables, will resolve problems with the reading order. If you have Acrobat 7 Professional, try using the TouchUp Reading Order tool to edit the reading order of a page or assign a new tag to an element. It has a much simpler interface and, depending on the simplicity of your PDF, could be used to tag and reorder all or most of the content.

Table headers

Tagging tables in Acrobat has always been a difficult thing, especially if you have headers that span multiple columns or have headers for rows. This plug-in can help make that process much easier.

CommonLook will open a window that will help you mark-up a table. You will notice three tabs toward the bottom half of the window labeled Table Properties, Cell Properties, and Physical View. We are going to focus on the features in the Cell Properties tab.

Once you have opened this tab, you can begin to edit the properties of a table cell. Start by clicking on a cell you would like to modify, then use the dropdown lists below the table to tag it as either a table header or table data cell. If you designate that the cell is a header, you can then assign it a scope of column, row or both.

CommonLook allows you to apply properties to multiple fields at the same time. Use Ctrl + click to select fields one at a time or Shift + click to select every field between two selected fields, then select the cell type and scope. This feature makes an otherwise tedious process quite easy. If you have a table with headings across the top, you can create properly tagged headings in just a few steps.

1. Use Shift + click to select all of the cells across the top row.
2. Select Table Header Cell from the Cell Type dropdown list.
3. Select Column from the Scope dropdown list.

If the table has headers across the side as well, follow the same steps selecting all the cells along the side and choosing Row from the Scope dropdown list. A more complex table might require more steps, but you get the idea how easy it can be.

I did encounter one problem with the table evaluation feature—the table requires both row and column headers to "validate." If it only has one or the other it will not let you select Pass. If you encounter this problem, just select Skip and move on.

Form elements

More than ever, people are creating PDF files that can be filled in online and either printed out or submitted. If you are using a PDF file to submit a form online, you may consider using HTML as it is typically more accessible and easier to use.

The CommonLook Plug-in performs an automated evaluation of forms. If there are any form elements not in a form tag, then the PDF fails that checkpoint. If all form elements are tagged, it passes. The plug-in does not check to ensure that form elements are associated with descriptions, or help you determine if the associated descriptions are appropriate.