: Here's the part I found frightening:

: << An International Skating Union presentation at the U.S. championships

: revealed yesterday some new details apparently adopted by the six ISU committee

: members who are tweaking the system.

: Everyone had already heard that 14 judges would be lined up to mark events

: under the new system, but that a random system would select the marks of only

: nine.

: But with a trimmed mean, the two highest and two lowest marks would be tossed

: out. That means that out of 14 original judges, only five marks would end up

: counting. >>

: From a statistical perspective, this seems questionable. Anyone with a math

: background wish to explain why (or how) this process would work?

It doesn't.

- According to the stats text in

my office (and this is just off the top of my head, people with better

statistical backgrounds feel free to correct me), in a population of 14, a

sample of 5 gives you at least a .0004 level of confidence that your

sample is representative - in other words, for every 1000 times you draw a

sample of 5 from that population of 14, 996 of those 1000 draws will truly

represent the opinions of the entire 14. This is statistically significant

(i.e. reliable) and would be considered meaningful in most situations.

HOWEVER this os only so if there is a normal distribution among the

entire sample, i.e. that a certain percentage of the population falls

within a

certain distance of the mean (the % vary slightly depending on the size

of the population, but the general "shape" of the distribution is the

same, like a snake that swallowed a basketball).

It's impossible to know whether

this is the case or not without seeing the entire set of 14 marks.

PLus...would you want to lose, say, Worlds if you happened to be the one

who got one of those 4 random draws that DIDN'T represent the opinions of

the entire panel?

- Tossing out the high

and low

marks makes minimal difference to the mean.

- There is no guarantee that the mean or the marks the mean is

derived from truly represent the

performance being judged. In other words, if you have a panel full of

Balkovs, there will be a mean, but it might have nothing to do with the

quality of the performance. All the mean says is "here is a number that is

the average of all the marks awarded" - there is no compensation for the

fact that those marks might be flawed in some way.

Fiona