So here's the situation: There are n balls. Each ball has been voted on a scale of 1-N by an arbitrary number of people.
Every day (or every week, or more), some/most/all of the previous voters and some new voters are able to vote on the balls again. The thing is, I don't want all previous votes to all disappear because the votes that were valid yesterday are still valid today. The re-votes/new votes will just be weighted "more".
There can be more OR fewer people who vote during the new voting session.
What is a good method of data decay for this? I have thought of taking the square root of "yesterday"'s votes every day/week, but that doesn't seem like it would work well if I have lots of voters in one day because the square root of the sum of the votes doesn't decay that "much" and if I have few voters, the square root of the sum of the votes can decay less and so the new, initial votes, will skew the result set. I could be wrong; I'm not sure.