I did some googling. I couldn't find any information more fresh than 10 months, so unless they changed something within last year, here's how it works:
You want to be at or above median, otherwise your score gets adjusted using the following formula:
sqrt(number of scores/median number of scores)
Median is not average, keep that in mind.
So let's say you only got 8 ratings, and median entry was rated 10 times. Your score would be adjusted using a factor of 0.89 also known as square root of 0.8. meaning that even if every score was perfect 5/5, your final adjusted score is now 4.45
This is meant to make sure that unpopular entry with one or two votes does not win over an entry with 100 votes, that managed to maintain it's high score. Which is fair to be honest.
If your score is at median or above it doesn't get adjusted anymore.
If you enjoyed reading that nerd stuff, I'm sure you would enjoy reading The Offworlder. It's an adventure which allows you to bring sci-fi elements into your fantasy world. SHAMELESS PLUG!