The big mistake experts make is in talking over the heads of their audiences. It’s hard enough to get your own thoughts down in black and white, let alone make them simple to read for others. But it’s absolutely vital that you do.
And there are two reasons:
1) If you confuse readers or make them feel stupid they are not going to come back
2) Google is constantly trying to work out how helpful your content is and lots of long sentences, complex words, and jargon sends all the wrong signals to the algorithm.
A good place to check your readability is www.read-able.com. Most tests are based on the required US education grade, starting with Grade 1 at 6-7 and Grade 12 at 17-18. Text for the general public should aim for Grade 10-12 or age 13-15.