I know it's comparing apples to oranges, but I contribute a lot on Stack Overflow so I took a look at the results. https://encrypted.google.com/search?hl=en&tb

I know it's comparing apples to oranges, but I contribute a lot on Stack Overflow so I took a look at the results. https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Astackoverflow.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... I was expecting a higher proportion in the "advanced" category. For comparison: Math Overflow: https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Amathoverflow.net&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... OnStartups: https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Aanswers.onstartups.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... English Language & Usage: https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Aenglish.stackexchange.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... CS Theory: https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Acstheory.stackexchange.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... Seasoned Advice (Cooking): https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Acooking.stackexchange.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... Physics: https://encrypted.google.com/search?hl=en&tbs=rl%3A1&q=site%3Aphysics.stackexchange.com&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai= https://encrypted.google.com/search?hl=en&tbs=rl%3A1&#38... It's no surprise really, but it seems like the more technical jargon used on a site, the higher the reading level Google assigns.