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Wutu Banale 
Forum Senior Member 
Joined: October 11 2006 Location: Finland Status: Offline Points: 104 |
 Topic: Ratings calculationPosted: July 17 2007 at 15:33 |
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This new system isn't good at all. The average for the albums are all screwed up and all. And the new thingy made TaaB go number 1. A spot it doesn't deserve
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Käsittämättömän käsittämätöntä
Suurta ja arvostettavaa. |
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XPEHOPE3KA
Forum Newbie 
Joined: July 13 2007 Location: R Status: Offline Points: 29 |
Posted: July 15 2007 at 11:08 |
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That's the key point! Leave the algorithm for ratings as it was (it took into account who gave the review and how "long" it was). But when you need to list the albums anywhere... It is this place where to use an algorithm which takes the number of reviews into account as well. So the ratings would remain in a state people got used to already (when a collab rate 5, and a noncollab rate 4 the average used to be equal to 4.60 or near - I guess, it was Ok for most visitors), and least reviewed albums won't pop up on tops of rating-lists or something. What's done now is going to make most popular albums even more popular and the least popular albums would receive even less attention. Visitors will just look at the rating (which is now modified by a number-of-ratings-dependent algorithm, but how a visitor would now THAT??) and see it is 3.89 or so - would they be willing to get it?? It doesn't attract even to read the reviews! Hope, you got my point of view: the current algorithm scheme is not that evident to an average visitor (it just isn't natural) and surely would make some potentially good albums unattractive. Edited by XPEHOPE3KA - July 15 2007 at 11:09 |
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MikeEnRegalia
Special Collaborator 
Honorary Collaborator Joined: April 22 2005 Location: Sweden Status: Offline Points: 21206 |
Posted: July 15 2007 at 09:36 |
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progressive
Forum Senior Member
Joined: October 08 2005 Location: Finland Status: Offline Points: 366 |
Posted: July 15 2007 at 07:40 |
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Yes, and no. It isn't listed above them, at least if there's tow ways to list them and users could choice the way. And the previous system worked well. And there's always top 100 (or 500) lists. There are lists for genres also. Why not for artists? It is only calculating, not taking too much resources. It is very odd that you must look into each album's ratings trying to calculate yourself the absolute average. And who says reviewers' ratings are better? Or that the album is better when there's more ratings. I think proggers are quite intelligent people and because there's so few ratings in many albums, we should take them seriously and not "banning" non-reviewers or single voices. And whatabout situation when there's album with three 4-star votes, one with two five-star votes? And Im still not sure if it is a weighting factor whether you are reviewer or not.... obscure. Very obscure things. Can't go on like this. Dying. |
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► rateyourmusic.com/~Fastro 2672 ratings ▲ last.fm/user/Fastro 5556 artists ▲ www.progarchives.com/Collaborators.asp?id=4933 266◄ |
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MikeEnRegalia
Special Collaborator
Honorary Collaborator Joined: April 22 2005 Location: Sweden Status: Offline Points: 21206 |
Posted: July 14 2007 at 06:53 |
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^ So you think that with two 5 star ratings the album should have a "score" of 5.0 and be listed above long standing albums with 4.x averages?
The weighted average simply means that new albums start with the combined average of all the albums in the database and then slowly work their way up. I like it, but I agree that on the website there should be an explanation of how the algorithm works, so that people don't think that it's simply broken. |
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progressive
Forum Senior Member
Joined: October 08 2005 Location: Finland Status: Offline Points: 366 |
Posted: July 14 2007 at 06:48 |
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It makes my life a lot more difficult!!
Though, i love and hate everything at the same time... http://www.progarchives.com/album.asp?id=13410 there's 3,77 for example, with two 5-stars. Maybe we should vote about it. Why are rating averages changed?? |
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► rateyourmusic.com/~Fastro 2672 ratings ▲ last.fm/user/Fastro 5556 artists ▲ www.progarchives.com/Collaborators.asp?id=4933 266◄ |
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Easy Livin
Special Collaborator
Honorary Collaborator / Retired Admin Joined: February 21 2004 Location: Scotland Status: Offline Points: 15585 |
Posted: July 13 2007 at 11:43 |
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What's the point in being angry about it?
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progressive
Forum Senior Member
Joined: October 08 2005 Location: Finland Status: Offline Points: 366 |
Posted: July 13 2007 at 11:02 |
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This is f*cked system, cannot work this way,,, and people fixing some random ratings...
weighted rating averages can remain, but only if we take the absolute average with it. People can check themselves who many ratings some albums have and whether a Reviewer has rated it. We can't go with the popular system because so many have only few ratings.  v v And where's the function who all is being calculated?? I think there could be many was to calculate things (for example three) but they should be shown clearly. And it would be nice if they were in tables that can be modified,, i mean, that the list could be ordered in many ways, for example by year or rating Edited by progressive - July 13 2007 at 11:06 |
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► rateyourmusic.com/~Fastro 2672 ratings ▲ last.fm/user/Fastro 5556 artists ▲ www.progarchives.com/Collaborators.asp?id=4933 266◄ |
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MikeEnRegalia
Special Collaborator
Honorary Collaborator Joined: April 22 2005 Location: Sweden Status: Offline Points: 21206 |
Posted: July 12 2007 at 09:01 |
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How about this:
SELECT @avg_num_votes = AVG(n_ratings) FROM CD WHERE n_ratings > 0 SELECT @avg_ratings = AVG(avg_ratings) FROM CD WHERE n_ratings > 0 AND avg_ratings IS NOT NULL UPDATE CD SET weighted_ratings = ((@avg_num_votes * @avg_ratings) + (n_ratings * avg_ratings))/(@avg_num_votes+n_ratings) WHERE n_ratings > 0 UPDATE CD set weighted_ratings = NULL WHERE n_ratings IS NULL OR n_ratings <= 0 I think it's important to make sure that empty CD entries (0 ratings) are excluded - the WHERE clauses make sure that this is the case. I also based the calculation of @avg_ratings on the computed average of the album - it should have a better performance since there are fewer rows to look at, and my guess is that that value also includes the reviewer weights which makes it a more accurate basis for the formula. Finally I added a WHERE clause to the UPDATE statement and a second UPDATE because for albums without ratings the calculation is not valid: (N*R+n*r)/(N+n) = N*R/N = R for n=0 and r=0 (in other words: Albums without reviews currently get assigned the average rating of all the reviews as their weighted rating). I hope this is helpful to you, M@x ... let me know if you have further questions!  Edited by MikeEnRegalia - July 12 2007 at 09:17 |
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M@X
Forum & Site Admin Group
Co-founder, Admin & Webmaster Joined: January 29 2004 Location: Canada Status: Offline Points: 4028 |
Posted: July 12 2007 at 07:21 |
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A major recalculations was made in the past hours, the Average Rating of a particular album is still the same though. And therefore should have fix the 1 rating issues and others , please get back to me ...
Now, the difference is in the TOP 100 list ... Before : Log N order by Now: Weighted Avg, comparing an album to all others album in the site The WR of an album is calculated like this: I weight the average number of votes and avg rating of albums against the average rating of a specific album. Every time a review/rating is posted I recalculate the WR for all the albums. Like this: SELECT @avg_num_votes = AVG(n_ratings) FROM CD SELECT @avg_ratings = AVG(CONVERT(FLOAT,rate)) FROM Rating UPDATE CD SET weighted_ratings = ((@avg_num_votes * @avg_ratings) + (n_ratings * avg_ratings))/(@avg_num_votes+n_ratings) and the weighted_ratings is used for the position in the TOP 100. What do you think ? Mike ? Max Edited by M@X - July 12 2007 at 07:23 |
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Prog On !
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Easy Livin
Special Collaborator
Honorary Collaborator / Retired Admin Joined: February 21 2004 Location: Scotland Status: Offline Points: 15585 |
Posted: July 12 2007 at 04:02 |
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Chers Mike, I've passed on your offer to M@x!
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Mandrakeroot
Forum Senior Member
Italian Prog Specialist Joined: March 01 2006 Location: San Foca, Friûl Status: Offline Points: 5851 |
Posted: July 11 2007 at 18:12 |
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Well... Is this the Artificial intelligence of the "2002 Space Odissey"'s computer, maybe?    |
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avestin
Special Collaborator
Honorary Collaborator Joined: September 18 2005 Status: Offline Points: 12625 |
Posted: July 11 2007 at 18:09 |
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Anomaly, yes... or a fine example of Artificial inteligence... Although judging by some of the albums that got a rating, an inteligence with not so good taste in music....
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Mandrakeroot
Forum Senior Member
Italian Prog Specialist Joined: March 01 2006 Location: San Foca, Friûl Status: Offline Points: 5851 |
Posted: July 11 2007 at 18:05 |
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If one album have zero ratings... The average is zero. Instead they come appraised also those albums. For me a serious anomaly!!! |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: July 11 2007 at 18:02 |
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Hopefully these anomalies are only affecting the albums with a low number of ratings/reviews, otherwise the entire Top 100 would be completely skewed - and I think someone might notice that and make a bit of a fuss.
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What?
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MikeEnRegalia
Special Collaborator
Honorary Collaborator Joined: April 22 2005 Location: Sweden Status: Offline Points: 21206 |
Posted: July 11 2007 at 17:53 |
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weighted average does not explain these anomalies ... either there are mistakes in the calculation, or M@x is doing something completely different. Either way, I'd be happy to take a look and maybe help him to find a solution.
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: July 11 2007 at 17:41 |
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M@x's link pointed to a Wikipedia page on the general principle of weighted averages and another link later on pointed to the comment at the top of the Top 100 page:
Here is some details about how we calculate the average rating of an album and the rank of an album.
Unfortunately that does not give details of the weighted algorithm itself, nor does it explain the anomalies that mentioned by Logan and others. |
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What?
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Logan
Forum & Site Admin Group
Site Admin Joined: April 05 2006 Location: Vancouver, BC Status: Offline Points: 35886 |
Posted: July 11 2007 at 17:34 |
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It's more than one album. 1309 albums in the top 4000 all-genres alone by my count last night. As I wrote in that other thread:
I wonder why do all the unrated albums in the top 4000 now have a value of 3.86 (by my fatigued checking)? I have a theory, but... I don't find that useful. Taken from the top 4000 most popular albums (CLICK): Every non-rated album in the top 4000 is given a rating of 3.86 and they all fall between 1224 and 2533 (they are surrounded by reviewed albums). Between 2882 and 3286 all the albums have 2 ratings and are given 3.83. Between 2881 and 3153, the first albums only rated once are found, and are given 3.84. And at 3379 to 4000 are all the other albums given one star - at 3.83. All of the albums only rated three times are given a score of 3.85, 3.84, or 3.83. The album at 4000 with one review/rating of 4 by Sean Trane which gets a list rating of 3.83. I see looking at the Kevin Ayers page that the album ratings do vary slightly between the albums only rated once... from 3.79 to 3.83.... |
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Easy Livin
Special Collaborator
Honorary Collaborator / Retired Admin Joined: February 21 2004 Location: Scotland Status: Offline Points: 15585 |
Posted: July 11 2007 at 17:25 |
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M@x provided a link somewhere (I thought it was in the PML thread) with a link to details of the algorithm. Don't know about the album with no reviews off hand. Logic dictates it should not have any sort of calculated rating.
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: July 11 2007 at 17:16 |
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the Thread is What happened to TOP 100???
However, that thread deals with the relative positions of the album in the Top 100, not how the weighted ratings are calculated.
Out of (now gnawing) curiosity, I would like to see the algorithm that is used to calculate each rating.
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What?
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Ratings calculation
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MikeEnRegalia wrote:
Come on, get a life!