PDF vs. HTML (take two)

There were a couple of good comments on my post regarding the differences in accessibility PDF and HTML and I wanted to follow up with some more thoughts on the issue. In the earlier post I referenced Nielsen’s anti-PDF article and a rebuttal to that article from McDaniels. While I may be ill-qualified and it may be somewhat ridiculous to rebut a rebuttal, I’d like to take issue with some of the points made in McDaniels rebuttal.

Here are some of the points made by Mr. McDaniels that I consider to be misleading along with my own thoughts:

If a web author has supporting materials like .DOC and .PPT files, it is easy to covert these to PDF rather than attempt to re-author the content for HTML.

Is it not just as easy to convert a Word or PowerPoint file to HTML as to PDF? Why would you need to re-author the content for HTML but not for PDF?

The content and flow of a PDF is the responsibility of the author not the PDF file format. I can employ the same web writing guidelines you recommend into a PDF file.

This is true, but the nature and functionality of Acrobat lends itself much more to designing documents to look like printed text, not a browser. While you can mimic the style of web content using PDF documents, the majority of users don’t- it takes too much time and is an unfamiliar use of the PDF format. Why try to mimic a format when you can use the real thing?

PDF’s can be displayed Full-screen in a browser to hide the Adobe reader interface, and they can be embedded in HTML as well.

First of all, my guess is that a majority of users are unaware of how to eliminate the Adobe interace that shows up in the browser- and if it is hidden many users are confused with how to interact with the document. How do you navigate through the document? How do you print? How do you zoom? If you are going to use PDF’s, it makes sense to keep the interface there- but doing so adds a entire second set of user controls for the user to worry about. If you want to print a PDF doc from a browser, do you use the browser print button or the Adobe Print button? Furthermore, when you click on a PDF link on some platforms/browsers it doesn’t display in the browser unless you have a specific 3rd party plugin. Instead it downloads it to your computer and you have to then go find it to be able to open it.

PDF file size is determined by the author. Images can be optimized automatically to produce fast loading files, and documents can be optimized for fast web viewing to allow page-at-a-time downloading of long documents. I’ve seen plenty of HTML pages that reference 1MB images.

Here the comparison is being made between good PDF design to bad HTML design. True, images can be optimized for both formats, but my experience is that when the same content is converted into both PDF and HTML format, the HTML is generally going to be a smaller file size. See
this case study.

I can build clickable buttons and links into a PDF. I can even mimic a website’s navigation bar at the top of a PDF to make things easier for the viewer.

Again, yes you can mimic website navigation using PDF- but why not just use the format that you are trying to mimic?

Lest I be misunderstood, I wholeheartedly that there are unique situations where PDF is a more appropriate forma, but I feel that those situations are rare. I have no way to test or validate this, but my assumption is that is someone is faced with the choice on a website of viewing the same content in either HTML or PDF format, most people are going to click on the links to view the HTML. Given a choice, most people prefer to view content in an HTML format. Anyone using any type of technology can access HTML- no plugins or 3rd party software required.

All that said, don’t take my word for it- lots of peoples have different opinions on the matter with some accompanying issues:
Which format should you choose?
How Do You Like Your Documentation
Search Engines and PDF