How to determine the accuracy of a statement?

Scenario:

Consider a statement, e.g. "This movie is an action" Then let people vote on that. 1-5 where 1 is "Not action", 3 is "Some action" and 5 is "Pure action".

Question

How does one determine how accurate the the statement from the voting result?

1000 votes where 900 is a 5 is pretty accurate, but 1000 votes with 500 1's and 500 5's is not very accurate. Also 3 votes and all a 5 is not so accurate.

Basically determine the certainty how much an object is of a specific category from uservotes.

I'm having some problem explaining my idea, but ask any questions and I'll try to clarify

• Do you have a 'ground truth'/answer key/etc? For example, if 900/1000 people vote the same way, is it possible that they're all wrong (e.g., you're showing them an optical illusion or perhaps they're all just dolts)? Commented Apr 11, 2012 at 9:22
• Not really. Basically I'm trying to let users decide what an object is. Ofcourse I can never be 100% sure that its correct, 900 people can be dolts. But I should be able to say that "It's blah percent chance that this is an ..." Commented Apr 11, 2012 at 9:25
• There's a similar thread that's gotten some answers:stats.stackexchange.com/questions/26054/… Commented Apr 11, 2012 at 10:36