CorTezz opened this issue on Dec 06, 2008 · 5 posts
CorTezz posted Sat, 06 December 2008 at 3:23 PM
Hey,
I was wondering how if I'm voting a picture with 1* and 3 others vote with 5* the average can possibly be at 5.0000 ?
According to my math skills it should be (35+11)/5 = 4.0000 ?
Greetings
PS: I've noticed this at several pictures.
nruddock posted Sat, 06 December 2008 at 4:01 PM
Quote - I was wondering how if I'm voting a picture with 1* and 3 others vote with 5* the average can possibly be at 5.0000 ?
The most likely explaination is that the average rating gets updated by a daily batch job rather than being recalulated immediately.
The other possibilities are too sad or comical to be worth worrying over.
rcook posted Sat, 13 December 2008 at 9:31 AM
If the average calculation works the same way today as it used to, it uses a standard deviation calculation to exclude outlying ratings. So in the case you mentioned, the "1" was an outlaying rating and was excluded from the rating calculation. But again, it used to be that way, maybe not exactly that today.
StaceyG posted Sat, 13 December 2008 at 3:48 PM
rcook is exactly right. It is done on the "standard deviation calculation"
Thanks!!
CorTezz posted Mon, 15 December 2008 at 2:04 PM
Ah.. That explains a lot. -.-
Thank you for the explanation.