Star Rating Breakdowns

NotWise said:

We're actually talking about different things.

I am saying that the back calculation of votes has a significant probability of error with more than 50 votes.

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Can you clarify what you mean by "back calculation" vs. "forward calculation"? I'm not familiar with that terminology.

What you have said is that you can use forward calculations to determine the exact number of votes. I won't dispute that, but I might suggest that doing so isn't very practical--especially if you don't start by doing the back-calculation first.

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I think you're rather overstating the difficulty. It just takes a couple of simple spreadsheet formulas and once it's set up, it can be used over and over. The slowest part is the data entry, which you'd have to do for any method. I'm willing to go to the trouble of typing an extra formula, once, for a method that gives perfect certainty up to 100 votes and doesn't estimate 6s.

This is a screenshot of voting results on one of my stories on the morning it posted.

The columns from left to right are the # of votes, score, estimated # of *s, the change in *s, the change in votes, then the estimated # of votes from one to five. If the number of votes cast (5th column) is one, then the change in the *s (4th column) is the estimated vote.

The screenshot shows obvious errors at 64 votes and 72 votes. The errors are only obvious because you can't get 6 *s from one vote. Any of the other estimated votes could also be in error.

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Nice scores!

For comparison, here's what I get when I do it my way, using the same inputs as your example. It took literally two minutes to set up this spreadsheet, and it gives exact numbers with no uncertainty and no 6s. From that table, I can figure out that you got exactly 24 five-star votes and 4 four-star votes during that period, with no 1s, 2s, or 3s... which is the answer to the OP's question. All that for far less effort than either of us have spent discussing the issue here.

For vote counts over 100, "unrounded score" and "change in stars" would be ranges based on min and max # of stars, but in this example there's no space between them so I've just left one column.

Think of the actual writing you folks could be doing.

Bramblethorn said:

Can you clarify what you mean by "back calculation" vs. "forward calculation"? I'm not familiar with that terminology.

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"back" calculate mean deriving the unknown # of *'s voted through a formula like:

T=round(N1*S1-N0*S0)

N1 and N0 are the current and previous number of votes
S1 and S0 are the current and previous ratings.
T is then the change in the total number of stars voted, which translates to the value of the vote if there's only one vote.

"forward" calculate means to derive the number of stars by finding out what is necessary to achieve the reported score, given the change in votes and the number of stars in the previous vote.

sr71plt said:

Think of the actual writing you folks could be doing.

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It's a good thought, but Saturday morning isn't great for writing for me; for some reason I find stories flow better at night.

Arguing mathematics, that I can do 24/7 ;-)

sr71plt said:

Think of the actual writing you folks could be doing.

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LOL. I say this to myself sometimes, especially when I've been complaining to myself about not getting a story done and instead am brainstorming a reply to something someone said on these threads.

sr71plt said:

Think of the actual writing you folks could be doing.

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I tell myself that too, yet here I am, reading all the new posts in my writing time.....