Need advise on the ratings addon

[Rob]

I am adding statistics to the ratings addon, but I need some advise. Can anyone with a math (stats) background give me some advise on what is more correct?

I am looking at the average rating for the photos on the site. The problem is, different photos have a different number of votes. So, I have two methods of getting the average, I just don't know which is more correct. I am leaning towards the second though.

1. Take an average of all votes cast. The problem with this is that pictures with a lot of votes could skew the average, but maybe that is correct.
2. Take the average of all of the average votes for each photo. This way, the rating for each photo is given equal weight, but maybe that is wrong because then a person voting once on one photo would have more weight than a photo with 10 votes.

What do you think?

[steff]

Originally Posted by Rob

I am adding statistics to the ratings addon, but I need some advise. Can anyone with a math (stats) background give me some advise on what is more correct?

I am looking at the average rating for the photos on the site. The problem is, different photos have a different number of votes. So, I have two methods of getting the average, I just don't know which is more correct. I am leaning towards the second though.

1. Take an average of all votes cast. The problem with this is that pictures with a lot of votes could skew the average, but maybe that is correct.
2. Take the average of all of the average votes for each photo. This way, the rating for each photo is given equal weight, but maybe that is wrong because then a person voting once on one photo would have more weight than a photo with 10 votes.

What do you think?

nor 1 neither 2!
i think pictures with more votes should really weight more, it makes sense to me.

BTW,
in this photo
http://steff.altervista.org/index.php?showimage=37
the number of votes never changes (2), while the rate does.

[Rob]

I am also giving you the picture with the most votes, but I also want to give the picture with the highest and lowest rank.

As for your one picture, that is very odd. You can vote twice, but only your last vote counts, maybe that is it? So, if you vote 1, then 5, the rating will change, but the number of votes will stay the same.