Ratings calculation

Easy Livin wrote: I think, and I'm speaking from shaky ground here, that the rating shown should not be seen as a straight average of the ratings posted.   It is a figure calculated by taking the rating or ratings of the album, running them through an algorithm which takes other factors into account, an coming up with a result. This result allows the album to find its relative position among all the others.   I know it looks strange that the figure shown for one album is not the same as the only rating for that album, but it reflects all the other constituent parts of the algorithm too.

I'm quite sure the calculation was OK in the past.
So there must have been changes during the last days which have forced this dilemma.
Maybe there is a chance to revert to a former state ...




Edited by Rivertree - July 11 2007 at 15:33

Unfortunately change my manner of to appraise the album!!!  

Easy Livin wrote: There has been a fundamental change to the algorithm used. See the thread in the Prog Music lounge.

Rivertree wrote: Easy Livin wrote: There has been a fundamental change to the algorithm used. See the thread in the Prog Music lounge. I can't find any thread in the Prog Music Lounge dealing with this problem

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....

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.

MikeEnRegalia wrote: 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.

If one album have zero ratings... The average is zero. Instead they come appraised also those albums.  For me a serious anomaly!!!

avestin wrote: Mandrakeroot wrote: MikeEnRegalia wrote: 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. If one album have zero ratings... The average is zero. Instead they come appraised also those albums.  For me a serious anomaly!!!     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....

Well... Is this the Artificial intelligence of the "2002 Space Odissey"'s computer, maybe?

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

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