Many major search engines now have the capability to index PDF files created by Adobe Acrobat and return them in search results. If you are a Web site owner with PDF files on your site, this is good news.

What you may not know is that this capability presents potential usability problems, especially for searchers. What is the big deal? Let's find out.

Searching for "blessing of a Christmas tree" on Google returns a link to a PDF file in the results. (www.usccb.org/publishing/advent2003/XMASTREE.PDF)

If searchers click on this listing, the link automatically opens a PDF file with no navigation to the main site. Users are trapped! They have no way to explore other pages of the site for more information.

So, what's going on and, more importantly, how to do we fix it?

Essentially, the PDF format is not the culprit; the real problem is the author's failure to create the files with Web users in mind. This is not unusual since pdf files are often documents created for other media and not specifically for the web.

PDF authoring software, such as Adobe Acrobat 5.0, offers the ability to include both a navigational structure and hyperlinks on a PDF page. This will allow users who land on this page from a search engine to continue to navigate the site. Whenever possible, use the built-in capability of the software to add navigational elements before publishing the document.

Ideally, the best solution is to create your pages in HTML, rather than PDF format. If the information contained in the pdf files is very popular or highly requested, consider making the effort to convert them to HTML for best results.

Depending on the purpose of the document, a PDF format can be preferable. For example, PDF files offer better functionality for pages that are highly structured and commonly printed, such as application forms and price lists.

To fix the PDF USER TRAP, you will have to republish your files, adding some type of navigation structure and/or link back your main Web site. An easy way to accomplish this is to add a footer to the bottom of each page that includes a link back to the home page. Often the pages published as .pdf files were never intended to receive traffic from the search engines in the first place. If you have .pdf files on your site you do not want to be accessible to the search engines, the best solution is to place all of your PDF files in a single folder and do a robots exclusion (http://www.robotstxt.org/).

Don't overlook the potential traffic from your .pdf files. Take a few extra steps to help users continue on to your site and you may be surprised and pleased by the results.

About author:

Craig Geis is the search engine specialist for the The Karcher Group (http://www.thekarchergroup.com), a full-service web design and marketing company based in Canton, OH.