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Old 11-14-2003, 11:57 AM   #22
Ted Marr
Location: Providence, RI
Join Date: Oct 2003
Posts: 94
When I read someone interpreting those results (seemingly) to mean that 13% of all people who do Aikido get concussions, I just feel the need to step in...

Ah, the sad results of being an ex-social sciences geek...

This sample cannot be taken as a valid representation of the entire population without some MAJOR "if's"

IF a random sample of Aikidoka visit this site, and

IF of those proportion a random sample answer the questionairre,

IF people are only answering once.

then you can start to say that we have really high injury rates.

However, I would guess that only people who are kind of "hardcore" are visiting this site, and they are more likely to get injured than casual practitioners. Also, people who have gotten concussions are probably more likely to answer the survey. I don't think the 3rd is a significant source of bias, but it's in there...

So hopefully we don't actually have a 13% (or whatever it was) injury rate...

Another thing I found interesting was that we seem to have confirmation that injuries as uke, and injuries as nage are not independent events... in other words, the same people who are likely to get hit in the head as nage are more likely to hit their heads as uke. Go figure...
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