

Ask HN: How to convert 5 star ratings to up/down voting? - rradu

I've got a site with close to a million ratings on thousands pieces of content. I'm redoing the site and I want to scrap the 5-star rating system and go for a like/dislike thing--sort of like what YouTube did.<p>The system will display how many votes there have been and the score (up votes minus down votes).<p>I want to keep all those ratings from the current setup, and still be at least a bit accurate with the scores (aka content that had higher star rating to have an appropriately higher score--of course this also depends on the number of votes which is why I don't exactly know how to go about it)<p>Suggestions?
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drKarl
Do you store each individual rating by each user or only the aggregate? If you
store each individual rating you could go two ways: A) \- If a rating is 3
stars or more, count as an up vote. \- If a rating is 2 stars or less, count
as a down vote.

B) Multiply the number of ratings for a given content by the .2xnumber of
stars aggregated for that content.

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rradu
Unfortunately I only store the total score and the number of votes

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pook
[http://www.aaai.org/ocs/index.php/ICWSM/09/paper/download/22...](http://www.aaai.org/ocs/index.php/ICWSM/09/paper/download/227/521)
may help. The polarization into "strongly like" and "strongly dislike" ought
to help.

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rradu
Yea it does help.

I can say the star rating is just an average of up and down. So if there were
10 votes and the rating was 3 out of 5, I can assume that means there were 6
up votes and 4 down votes for a score of 2.

This sounds promising.

