Re: NEC-LIST: Accuracy vs precision

Agreed; valuable remarks -- especially the benefit(s) of a high degree of repeatability
(and/or stability) with the intent of a later comparison *a transfer* to some 'absolute'
standard, to determine the non-random (systematic, offset or bias) part of the
overall error.........

At 10:16 AM 1/13/2003 -0800, Tom Bruhns wrote:
>That sounds like the definitions I learned long ago. Actually,
>precision, if it's repeatable, is worthwhile, too, in that you may
>be able later to calibrate and correct earlier measurements. For
>example, I can make frequency measurements based on a very stable
>oscillator which is not properly calibrated, and later (or at
>essentially the same time) measure a primary frequency standard to
>generate a correction factor. I may be able to trust the oscillator
>to be stable, for example, to one part in 10^9, but know that it was
>not initially set accurately to even one part in 10^6. So in
>addition to "accuracy" and "precision", I think it's worthwhile to
>mention "repeatability" and/or "stability".
>
>Cheers,
>Tom
>
>
>alan.boswell_at_baesystems.com wrote:
>>
>> Dan
>> Thanks for your comments and the dictionaries I looked up define 'accuracy'
>> as 'conforming to a standard or to truth' while 'precision' seems to be more
>> concerned with the number of decimal places quoted: the New Penguin
>> Dictionary of Science says that to state that pi is equal to 3.452546 would
>> be precise but significantly inaccurate. So accuracy is worth having,
>> precision on its own is not - does that agree accurately with your
>> remarks?
>> Alan

Dan Bathker

-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list