Jean-Philippe Magué told me there was a Google advanced search filter that checked the result pages to give a readability estimate. In fact, it was introduced about seven months ago and works to my knowledge only for the English language (that’s also why I didn’t notice it).
The most interesting bits of information I was able to find consist in
a brief explanation by a product manager at Google who created the
following topic on the help forum : New Feature: Filter your results by
Note that this does not seem to have ever been a hot topic !
Apparently, it was designed as an “annotation” based on a statistical model developed using real word data (i.e. pages that were “manually” classified by teachers). The engine works by performing a word comparison, using the model as well as articles found by Google Scholar.
In the original text :
“The feature is based primarily on statistical models we built with the help of …