15 May
Adobe Acrobat’s Portable Document Format (PDF) is a great file format primarily because it allows documents formatted for printing to be sent electronically in a format that is viewable on nearly all operating systems. This includes things like formatted mathematical formulas, inline images with text wrapped around them, page-based layout, columns and all the niceties usually associated with printed documents. Of course, Adobe has added lots of features over the years, including clickable indices and bookmarks, inline hyperlinks, etc. Despite all of this, you should not use PDFs to deliver content on your website.
There are a few legitimate reasons why you might need to use PDFs to provide downloadable content, particularly if that content needs to be usable offline, or to use mathematical formulas, or to be searchable. GeoShell, for instance, has an online wiki for documentation, but provides a downloadable copy of it as a PDF file so that users can access the documentation offline and have it be searchable and everything. But again, in general, you should not use PDFs as part of your website.
There are a lot of reasons why you should not use PDFs on your website. For starters, they’re generally bigger than HTML files, they force users to load another application, and they force a different form of interaction. Some (few) users might not even have Acrobat Reader installed (remember, Windows doesn’t include a viewer). Many savvy users resent PDFs and actively avoid them when possible because they don’t want to run the extra software (why do you think Google has a “View as HTML” option for PDF links?)
But the coup de grA?ce is usability. If you still can’t see why PDFs should be avoided, let me tell you story of how a PDF affected a friend of ours, and in fact, how PDFs may be affecting some of your users, those people you seldom hear from, who are actually the end target of all your labor.
Actually, it was a call for my wife — I happen to be at home sick today, still suffering from some sort of cold or flu — and the person on the other end had a question for my wife about cooking for hundreds of people (something my wife is very good at) ... but when she realized she had me on the phone instead, she said: “Hey, you’re a computer person, maybe you can help me with something…”
Now, many of you “computer people” out there are probably cringing, because you’ve probably spent countless hours both in person and on the phone trying to diagnose bizzare computer malaise, but stick with me. After we got the message for my wife out of the way, this caller (who shall remain anonymous for our purposes) went on to explain to me her problem:
“Ok”, she said, “You know they’re having this convention at Elim Fellowship this week. Well I went to their website to register for it, and I found the form, but it has that little hand, and I can’t type in it.” “Little hand?” I asked, thinking perhaps she meant the indicator we usually see for links … “Yeah, you know, the one they use when they don’t want me to be able to copy anything,” she said. Now, to be perfectly honest, at this point I was totally lost — You probably aren’t because I already gave away the ending of the story, but stick with me anyway.
After several moments of diagnosing, during which I determined that she was indeed trying to fill out a form online for a conference that’s running this week, and she was using “fox … fire … something, you know?” ... I had her reload the page, and she started talking about a menu she got from “clicking on the hand button that’s just like the hand cursor” which made me wonder if there was an extension or something … after checking that she had no extensions installed (yes, this is why Firefox should include some of their best extensions by default, but nevermind). So finally, I fired up my browser and asked her to read me the address. Just as she was getting to the file name … “2006_Conf…” it hit me! “Does this end in pee-dee-ef?” I asked, “yes, how did you know?” ...
So, I explained to her that the conference organizers probably hadn’t been smart enough to make their PDF a submittable form (although they arguably could, and should have), and as I was explaining that most people use PDF for forms only when they expect you to print it out and fill it in by hand and mail it in … she exclaimed that she had “hit the back button a couple of times, and found a link to a version I can fill out on-line” and thanked me very much for my patience.
Now, I don’t know about the rest of you who consider yourselves web designers, but I’m personally a big fan of usability, and to me, this screams of something that should be avoided at all costs. Basically: the website had a PDF with a link like: “Here is the brochure for more information” ... because they’d spent all this money on the printed brochure, and wanted to show it off. As a result, there weren’t any details on the web page itself (forcing anyone interested in the conference to read the PDF brochure). The registration form was on the last page of the brochure, and thus, at the bottom of the PDF. The problem occurred when a user didn’t realize that this document wasn’t like other web pages … had no idea, really, that she was in a different application, embedded in her browser… so essentially, the PDF broke her web browser.