If you DON'T give your traffic a REASON to stay, it will NOT stay
I just have found that Google has added new feature to its advance search. I think this feature is being tested and available to experience on few IP addresses only. It shows results on the basis of their reading level. Sounds little weird right? Well Matt cutts hasn't announced anything about this feature yet.
While I was using this feature I got results on the basis of selected reading levels. I tried different keywords but, couldn't figure out on what basis I was getting results, only one thing that I could understand is, results were different for each reading level. Mainly this feature has 3 reading levels 1) Basic 2) Intermediate and 3) Advance.
I think this feature classifies and shows results on the basis of grammar and difficult terminologies used in the site's content. Let's see what exactly Google is going to provide us with this feature.
Visit Official Announcement Page for Reading Level Feature.