The following has little or nothing to do with the above debate...
So you're making a website, or perhaps a legal document, or maybe just some documentation on software, and you have some text you have deemed to be very important, like headers for instance. Since they're so important, you might decide, let's put it in ALL CAPS!
How about "no"?
Denizens of the internet have long considered chatting in all caps "yelling" and therefore rude. But that's not the issue I'm taking with all caps here. Did you know that, as well as sometimes looking rude, text in all caps is less readable?
That's right. Studies and software/website/webware usability tests have shown that text in ALL CAPS is 13 to 20% less readable. That's right, I said less. Counter to what a great number of us have been taught, or assumed, putting text in all caps will not make them more readable - quite the opposite. It may make it more noticeable, but that won't necessarily make it more readable. Therefore, if you have something really important to say, it is actually not a good idea to PUT IT IN ALL CAPITAL LETTERS.
I personally attended Human-Computer Interaction seminars at a conference in June, 2006 with the Nielsen / Norman Group - a consulting firm - out in San Francisco, California. A good deal of all the seminars discussed the importance of usability, whether it be for software or websites. In one lecture the instructor talked about how all caps was less readable. It wasn't until he pointed out that I really noticed that it was true the next time I read a block of text in all caps. And then I saw that fact in action in another seminar where they showed us footage of actual usability tests. In one a woman was instructed to go to a website and find "Investor Relations" information. It took her upwards of ten minutes and many lookovers of a the About Us page to find it. It was very painful to watch her skip over the "INVESTOR INFORMATION" link time after time after time (we watched a split screen, one of her, and one of the website as she was looking at it, her cursor went right over it far too many times!). The fact that it said "Information" instead of "Relations" was only one problem (people have grown quite used to the term being "Investor Relations" - there's a whole lecture there about web terminology standards). The other was that the link was in all capital letters.
To knock the point out of the park, we saw many more examples of users not noticing or not reading headers, or even worse, navigation items on websites only because they were in all caps. And every single disclaimer page, with all the legalese, was a bad example of this practice. Lawyers tend to make things in all capital letters that they think are most important, which often can entail entire paragraphs, without realizing that those blocks of text will actually be the least read. This is assuming, of course, that anybody is reading that legal crap to begin with.
Still not convinced? Try reading the following two paragraphs that are identical except for their cases. Time yourself if at all possible. Or just notice, viscerally, which has a more readable feel to it, which is easier for your eyes to process.
MANY PEOPLE, ESPECIALLY LAWYERS, DO NOT REALIZE THAT PUTTING TEXT IN ALL CAPITAL LETTERS IS ACTUALLY LESS READABLE. THEY PUT LARGE BLOCKS OF TEXT IN ALL CAPS NOT REALIZING THAT ALL THEY ARE DOING IS CREATING LARGE WALLS OF TEXT THAT ARE NOT LIKELY TO BE READ, MUCH LESS UNDERSTOOD EFFICIENTLY. THIS IS A CONVENTION, LIKE MANY OTHERS, THAT IS MIRED IN SUPERSTITIOUS TRADITION AND IS EMPLOYED OVER AND OVER AGAIN JUST BECAUSE IT HAS ALWAYS BEEN DONE AND WITHOUT ANY SERIOUS THOUGHT ON THE PART OF THE CONTENT WRITERS OR DESIGNERS.
Now try this...
Many people, especially lawyers, do not realize that putting text in all capital letters is actually less readable. They put large blocks of text in all caps not realizing that all they are doing is creating large walls of text that are not likely to be read, much less understood efficiently. This is a convention, like many others, that is mired in superstitious tradition and is employed over and over again just because it has always been done and without serious thought on the part of the content writers or designers.
The difference can be subtle, I know, but notice how many times in the all caps paragraph that you may have had to reread a word or two or back up any because it felt like you missed something. That is where that 13 - 20% less readable figure comes in. Notice how much easier it was to read the second paragraph.
I'm not saying never use all caps for headers or buttons in navigation. But I am saying if you have to use it, use it sparingly. You might think it looks cool stylistically, but one thing I learned at the conference is that a lot of things us designers like to do to websites to make them look cooler might actually detract from its usability and for many websites usability is more important than looks. So if you have content that is really important, make sure that - in the case of a website - the link to it and/or the content itself is in lower case or mixed caps.
rootbeer227 says: "...could you add what you have shown but not explicitly said: that italics is usually the proper option for emphasis? (i.e. only, less)"
Yes. But I prefer bold wherever it's acceptable. And I also have an affinity for small caps. No studies have been done, as far as I know, on the readability of small caps. And you can only accomplish that in CSS.
rootbeer227 replies: "...I generally use boldface for key words and phrases rather than emphasis. Things that, were you reading a textbook, would appear in the glossary. Also, headers."
www.mcneese.edu - HTML version of a PDF
dr-bob.org - HTML version of a PDF