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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: accuracy
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Date: Fri, 9 Mar 2007 09:33:41 +0100
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On Thu, 08 Mar 2007 21:18:11 GMT, Bj�rn Persson wrote:

> Dmitry A. Kazakov wrote:
> 
>> If it were just inaccurate then the obtained values would be like
>> ThreadTime + Error where Error has zero mean.
> 
> No, that's "imprecise".

No. The sets "accurate" and "precise" do not contain each other. Which
means that measurement can be precise and accurate, precise but inaccurate,
imprecise but accurate or imprecise and inaccurate.

As for GetThreadTimes, its absolute precision is 1ms. Its suggested
absolute accuracy should be one time quant (which duration depends on the
system settings). The later does not hold, because the error is in fact not
bounded.

> Shots distributed evenly over a shooting target is
> bad precision. A tight group of shots at one side of the target is good
> precision but bad accuracy.

That's right. This is why GetThreadTimes is not just inaccurate, it is
precisely wrong.

BTW, precisely wrong /= imprecise. (:-))

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de