While I agree with the spirit of the article, this is one of those cases where a Bayesian treatment is conceptually much clearer. Assume that ratings are being generated by a stable stochastic process where the underlying distribution is multinomial (ignoring the ordinal character of ratings, for the time being) and use a dirichlet conjugate prior. This gives you a posterior distribution over new ratings for an item.…
Here's a paper proposing a solution in that space, and which also compares itself to the article linked here (kind of nice to see... papers sometimes fail to cite stuff that's "only" posted online rather than properly published, even if the authors know about it and it's quite relevant): http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... I emailed Miller a while ago to see what he thought of this reply,…
How Not To Sort By Average Rating
91–100 of 159 posts
Re: How Not To Sort By Average Rating
#92While I agree with the spirit of the article, this is one of those cases where a Bayesian treatment is conceptually much clearer. Assume that ratings are being generated by a stable stochastic process where the underlying distribution is multinomial (ignoring the ordinal character of ratings, for the time being) and use a dirichlet conjugate prior. This gives you a posterior distribution over new ratings for an item.…
Here's a paper proposing a solution in that space, and which also compares itself to the article linked here (kind of nice to see... papers sometimes fail to cite stuff that's "only" posted online rather than properly published, even if the authors know about it and it's quite relevant): http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... I emailed Miller a while ago to see what he thought of this reply,…
Re: How Not To Sort By Average Rating
#93While I agree with the spirit of the article, this is one of those cases where a Bayesian treatment is conceptually much clearer. Assume that ratings are being generated by a stable stochastic process where the underlying distribution is multinomial (ignoring the ordinal character of ratings, for the time being) and use a dirichlet conjugate prior. This gives you a posterior distribution over new ratings for an item.…
I would absolutely love to learn more. I've been trying to solve some novel NLP and machine learning problems lately but my lack of statistical knowledge is becoming apparent the further along I get. Do you have any recommendations for a good introductory treatment of Bayesian statistics?
http://www.inference.phy.cam.ac.uk/mackay/itila/book.html
Videolectures has some very good videos as well. Zoubin Gharamani has a pretty solid lecture on Bayesian learning at http://videolectures.net/mlss05us_ghahramani_bl/ (he's a great researcher but not the most engaging speaker). Try Christopher Bishop's lecture at http://videolectures.net/mlss09uk_bishop_ibi/ as well, it might be slightly more palatable.
Re: How Not To Sort By Average Rating
#94Re: How Not To Sort By Average Rating
#95Re: How Not To Sort By Average Rating
#96Original author here. For the academically inclined, there is a critique of this approach in this paper: http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... Of course, I think the authors miss the point of the algorithm, since I basically wanted a system that is one-sided (i.e. false negatives are OK but false positives are bad). Also, if you deal with more than two outcomes you might be interested in mul…
Would it be reasonable for 5 stars to normalise the data? Should star ratings be on some distribution, for instance?
Re: How Not To Sort By Average Rating
#97While I agree with the spirit of the article, this is one of those cases where a Bayesian treatment is conceptually much clearer. Assume that ratings are being generated by a stable stochastic process where the underlying distribution is multinomial (ignoring the ordinal character of ratings, for the time being) and use a dirichlet conjugate prior. This gives you a posterior distribution over new ratings for an item.…
Here's a paper proposing a solution in that space, and which also compares itself to the article linked here (kind of nice to see... papers sometimes fail to cite stuff that's "only" posted online rather than properly published, even if the authors know about it and it's quite relevant): http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... I emailed Miller a while ago to see what he thought of this reply,…
Here are slides from that paper's presentation, for a quicker overview: http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2...
Re: How Not To Sort By Average Rating
#98Original author here. For the academically inclined, there is a critique of this approach in this paper: http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... Of course, I think the authors miss the point of the algorithm, since I basically wanted a system that is one-sided (i.e. false negatives are OK but false positives are bad). Also, if you deal with more than two outcomes you might be interested in mul…
Re: How Not To Sort By Average Rating
#99I love it and I hate it. Why I love it: It's precise. It's elegant. It's rigorous. It's based upon solid, proven science & theory. It's a perfect application for a computer. And most of all, it does what's intended: it works. Why I hate it: What human can understand it? I used to implement the first manufacturing and distribution systems that used thinking like this. They figured, "We finally have the horsepower to a…
>What human can understand it? Lets start with Wilson's midpoint, since that's just high school math. def mid(upvotes:Int, downvotes:Int) = { val total = upvotes+downvotes+0.0 val up = upvotes/total val half = 0.5 val a = total/(4+total) val b = 4/(4+total) a * up + b * half } So there are two weights a and b. Using these weights, the midpoint is a weighted average of half and the proportion of upvotes. It should be…
Re: How Not To Sort By Average Rating
#100Original author here. For the academically inclined, there is a critique of this approach in this paper: http://www.dcs.bbk.ac.uk/~dell/publications/dellzhang_ictir2... Of course, I think the authors miss the point of the algorithm, since I basically wanted a system that is one-sided (i.e. false negatives are OK but false positives are bad). Also, if you deal with more than two outcomes you might be interested in mul…