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How Not to Sort by Average Rating (2009)

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Re: How Not to Sort by Average Rating (2009)

#81

Post by gesman »

kstenerud wrote: post #7

That's what's always annoyed me with Amazon's "sort by average rating" setting. I want to see the top 10 or so items by rating to give me a baseline to investigate from, but instead I get page after page of cheap Chinese crap with one 5-star review each from the resident fake reviewer. Worse than useless. Even a simple change like adding a "show only items with a minumum of X reviews" would be a godsend.

There is a good plugin for Chrome "Amazon Sort - Number of Reviews".

It helped me to push chinese crap way below the fold and focus on well-researched items on top.

Re: How Not to Sort by Average Rating (2009)

#82

Post by KVFinn »

paulgb wrote: post #4

Averages (even with the post's approach) still have the problem of not being "honest" in the game theory sense. For example, if something is rated 4 stars with 100 reviews, a reviewer who believes its true rating should be 3 stars is motivated to give it 1 star because that will move the average rating closer to his desired outcome. A look at rating distributions shows that this is in fact how many people behave. Med…

>Averages (even with the post's approach) still have the problem of not being "honest" in the game theory sense. For example, if something is rated 4 stars with 100 reviews, a reviewer who believes its true rating should be 3 stars is motivated to give it 1 star because that will move the average rating closer to his desired outcome.

Also I'd like to know if a 5/10 rating is mostly 5s, or an average of mostly 1s and 10s.

Re: How Not to Sort by Average Rating (2009)

#84

Post by baddox »

paulgb wrote: post #4

Averages (even with the post's approach) still have the problem of not being "honest" in the game theory sense. For example, if something is rated 4 stars with 100 reviews, a reviewer who believes its true rating should be 3 stars is motivated to give it 1 star because that will move the average rating closer to his desired outcome. A look at rating distributions shows that this is in fact how many people behave. Med…

If it's true that a significant number of people give 1-star reviews to drive down the average (I'm skeptical without seeing evidence), then would people really understand the idea of median ratings and stop doing that?

Re: How Not to Sort by Average Rating (2009)

#85

Post by albedoa »

crazygringo wrote: post #58
dntrkv wrote: post #46

Earlier quoted context omitted.

I've been saying this for years, thumbs up/down is the only system that makes sense to me. Foursquare uses it and I've found their scores to be way more useful than Yelp's. The biggest problem with star ratings is that it's so arbitrary. What is the difference between 3 and 3.5? What is a 1 vs a 2? 3/5 is 60%, that's almost failing when you think about it on a grading scale, if I scored something as a 3/5 I would nev…

Counterpoint: I almost solely rely on the stars histogram in Yelp (available only on the website, not the app), completely ignoring whatever Yelp's calculated "average" is. If a place has more 5-star ratings than 4-star ratings, it's generally amazing. If it has more 4-star ratings than 5-star ratings, it's generally fine but not something particularly special. Just thumbs up/down would eliminate what is, to me, the…

I pay a lot of attention to histograms when there are many high-rated options for the same Amazon product type. A histogram that curves sharply in its number of 5-star reviews to almost nothing on the other end is the product you want (ignoring fake reviews for the sake of this conversation).

Amassing a bunch of 4- and 5-star ratings is easy, but leaving nothing for even the most habitual of complainers to complain about? That's an monumental achievement.

Re: How Not to Sort by Average Rating (2009)

#86

Post by panic »

paulgb wrote: post #4

Averages (even with the post's approach) still have the problem of not being "honest" in the game theory sense. For example, if something is rated 4 stars with 100 reviews, a reviewer who believes its true rating should be 3 stars is motivated to give it 1 star because that will move the average rating closer to his desired outcome. A look at rating distributions shows that this is in fact how many people behave. Med…

You can also model each vote as an "agent" that tries its best to move the star rating toward its desired value. If the current rating is a 4, each "agent" with a vote less than 4 will throw a 1 into the average, and each vote greater than 4 will throw a 5. This process converges, though the rating tends strongly toward 3 (or whatever the middle value is).

Re: How Not to Sort by Average Rating (2009)

#87

Post by hammock »

hyperpape wrote: post #15
paulgb wrote: post #4

Averages (even with the post's approach) still have the problem of not being "honest" in the game theory sense. For example, if something is rated 4 stars with 100 reviews, a reviewer who believes its true rating should be 3 stars is motivated to give it 1 star because that will move the average rating closer to his desired outcome. A look at rating distributions shows that this is in fact how many people behave. Med…

John Gruber has been arguing that the only meaningful way to do ratings is a simple thumbs up/thumbs down. I don't necessarily agree, but I see the appeal. I usually don't want ratings, I want the Wirecutter treatment. Sometimes, I know/care enough to really research the topic, in which case star reviews are relatively unhelpful. The rest of the time, I just want someone trustworthy to say "buy this if you want to pa…

Offering a five stars to the rater can cause them to treat it as a thumbs up/thumbs down (as your parent comment alludes to when he references "game theory" and giving a one-star), with one star being the most powerful thumbs down, the obvious choice.

The other alternative is for users to actually SORT and RANK all products in that category that they have reviewed. Not a tenable solution.

Side comment, the Yelp histograms ARE useful... but that is more of a side effect/emergent from a bad rating scheme than anything else. Because people are using the stars not ideally, the histogram gives you insight into that. So it's not a bad solution, but a better solution would be something other than the stars.

Re: How Not to Sort by Average Rating (2009)

#89

Post by ghaff »

stinkytaco wrote: post #69
dntrkv wrote: post #46

Earlier quoted context omitted.

I've been saying this for years, thumbs up/down is the only system that makes sense to me. Foursquare uses it and I've found their scores to be way more useful than Yelp's. The biggest problem with star ratings is that it's so arbitrary. What is the difference between 3 and 3.5? What is a 1 vs a 2? 3/5 is 60%, that's almost failing when you think about it on a grading scale, if I scored something as a 3/5 I would nev…

If the provider is in a position to provide a prediction, then the rating system is useful. For example, on Netflix I used the Hated It, Didn't Like It, Liked It, Really Liked It and Loved It system. When they predicted a star rating, it was pretty close. When they said we predict you'll give this a three star rating(which is probably well below the "average") that was generally a movie I liked.

Which, in practice, tends to devolve to what's effectively a four-star rating of some sort: Want two hours of my life back, OK/meh, Good, Excellent

A humorous take: https://xkcd.com/1098/

Re: How Not to Sort by Average Rating (2009)

#90

Post by ghaff »

jonknee wrote: post #44
hyperpape wrote: post #15

Earlier quoted context omitted.

John Gruber has been arguing that the only meaningful way to do ratings is a simple thumbs up/thumbs down. I don't necessarily agree, but I see the appeal. I usually don't want ratings, I want the Wirecutter treatment. Sometimes, I know/care enough to really research the topic, in which case star reviews are relatively unhelpful. The rest of the time, I just want someone trustworthy to say "buy this if you want to pa…

Even Netflix finally moved over to up/down and they were famous for squeezing every drop out of their previous star based reviews [1]. In theory stars work better, but the issue seems to be everyone has a different ranking system. For example, Uber seems to think anything but a 5/5 is a failure. I know this so I skew to accommodate, but in my personal ranking system I've only had a couple 5 star rides (someone really…

This was (is? I haven't really used them much in a while) an issue with eBay's reputational system as well. Anything other than a Positive and "A++++++++++++ seller" was interpreted to mean they shipped you a box full of bricks rather than they took a week to ship things.
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