Readability is King
If you have to choose between form and function, function should win. So when you revamp your website, what should be of primary concern? The text, certainly. You have readers because of what you say. The design of the site should therefore serve the purpose of readability.
Legibility is Clarity
Note that there is a difference between readability and legibility. Being legible means that you can make out the letters; they’re not too distorted to hinder your ability to recognize them. Software coders are using this insight when they use a monospaced typeface to carry out their work. The characters line up perfectly so they can keep track of their levels, and each character is noticeably different from the rest. When characters are clear and differentiated enough from the rest, they are legible.
Readability is Simplicity Plus Excellence
On the other hand, readability is all about how little one has to work in order to breeze through long sections of text. This level of consideration takes into account the legibility of each character as well as the level of comfort (or discomfort) a reader experiences when plowing through the latest textbook on art history or pathophysiology. When text is easy and enjoyable to read, it is readable.
Part of measuring readability is in noticing how readily the characters, and therefore the words and paragraphs and pages, match up to our perception of character shapes. If it looks like an r, we don’t question it. If we have to question it — even for a moment — our reading progress stalls. This is the simplicity part of attaining readability; how one goes about making an r look like an r is where excellence comes in.
Our brain is fantastically adept. Studies have shown that literate adults do not sound out each individual letter, but match the shape of the word to a known word shape we have already memorized. Studies have also shown that when the first and last letters are correct, the middle letters can be jumbled but we will still be able to recognize, or “read”, the wrod corertectly. I know yuo’re stlil follwoing waht I’m siyanig here, but you can’t read comfortably like that for too long so make sure your text is readable. Make it simple and excellent because readability is king.
This was just a primer on the difference between legible and readable text. Stay tuned for a few articles to help with choosing typefaces for sizable amounts of text.
UPDATE: Here’s three links to articles on similar readability studies: