The next-to-last chapter of Don't Make Me Think is about accessibility. This is one of the most misunderstood topics in web development, so I was please to see it tackled in this book. The material is a little thin, but makes some good points.
Accessibility is something that nobody likes to talk about. The reason is simple, nobody does it well, or at least not as well as they wish they did it. Krug makes a good point that this often makes people simply give up and do nothing, when even doing a little is much better than nothing. In that vein, I like Krug's three-second test: changing the font size on a page to make it easier to read the text.
I especially liked this test because I often only think about screen readers when it comes to accessibility. Screen readers are very important to think about, but it is good to make sure you get some of the "simpler" stuff done right as well.
Often when I am thinking about accessibility, it is in the context of rich internet applications. These are applications with more advanced user interfaces with lots of code executing on the client. They are not the simpler dumps of HTML that most applications are. Accessibility can be very tricky with these applications.
In particular, it is tricky with Flash. All that comes to the browser in Flash is a binary file that is interpreted by the Flash Virtual Machine. I went to a couple of sites that are heavy in Flash and tried out Krug's three-second test. Flash sites do not do well. The Flash Player does not respond to the browser increasing or decreasing font size to make test more readable. I did find a very clever piece
on how to get Flash applications to do this. Unfortunately while the solution is clever, it is non-trivial to say the least. The demo given only shows the "scale the whole SWF" approach, i.e. make the entire Flash application grow in size when the text size is increased. That is a reasonable approach, but there are sure to be time when it is not appropriate and it will be much more desirable to only increase text. One can imagine a highly graphical application with sparse amounts of text for example.