Dave Wood wrote to me the other day:
I was somewhat aghast at finding one of my web pages coming in at a fog reading of 15+ - I'm just in the middle of revamping it now and am determined to have an index below 9.
I did find a glitch in a site you'd recommended: Readability.info. It wasn't accepting my files and seemed to convert them to a read-only in my own files. I had to re-start the computer to get rid of that setting. It may be local to my computer?
I did find another site that worked better in that it didn't require me to upload my files but accepted a paste: Gunning Fog Index.
I've had a similar problem with Readability.info. When I try to upload a Word file, it instantly tells me it found no sentences. Put in a URL, however, and equally instantly it provides a number of readability indices. I've written to the owner of the site, and will pass along his response. (Update: He tells me the problem arose after a switch of servers. Look for a fix after Christmas.)
In the meantime, while it's helpful to know the general readability of your website's text, you can do a lot just by following a few simple practices:
1. Keep text columns narrow.
Ideally, the longest line in a column should be 15 words. Ten would be better.
2. Keep words short.
"Magic" is better than "prestidigitation." "Idea" is better than "conceptualization."
3. Keep sentences short.
On some of my blogs, I excerpt articles from print media. Too often, especially in the first paragraph, a sentence goes on for well over 20 words. I don't rewrite such sentences, but I wish I could. Bulleted lists can often replace strings of words and phrases.
4. Keep paragraphs short.
In most fonts used on websites, six or seven lines should be enough for a paragraph. Even if it's a long, complex idea that belongs in a long paragraph, break it up. A long, solid mass of screen text will discourage too many potential readers.
5. Put a little white space between paragraphs.
A short line at the end of a paragraph isn't enough of a break. Just one hit on the Return key can make a world of difference in helping people read your text.
6. Put important words and phrases in "hot spots."
Your sentence's beginning and end are its hot spots. Here readers pay most attention and react most strongly to what they read. Hot spots cool off in sentences buried in mid-paragraph. Then the end of the last sentence becomes hot again.
So a paragraph starting with "There" or "It" has wasted a good hot spot.
7. Use bolded subheads to help navigation.
A subhead every few paragraphs gives readers an overview of the whole document. A numbered list like this one, with bolded and numbered lines, is also easier to understand.
8. Break these rules when you must.
Follow them too closely, and your writing style may start to sound dull and predictable. Too many short sentences (and bulleted lists) will give you too many hot spots. That will make you sound as if you're ranting.
The above text, pasted into the Gunning Fog site, turns out to have a Fog index of 7.396. Out of 517 words, 47 have three or more syllables. I did some revision while writing it, but 7.396 seems like a reasonable level of clarity.
A link to the Gunning Fog Index site is now in the Webwriting Resources list in the left-hand column.