RE: what good is "percentage error"?

[PHRP@FHSUVM.FHSU.EDU (Roger A. Pruitt)]

I think you have the right idea by saying that you are off by 5%. However,
you need to also say that in my one measure "I am off by 5%." (Maybe this is
the average of five measurements so then your statement would have to be
modified.) 

The objection as I see it is to call the 5% a percentage error. You are
making a comparison so say the percentage deviation in my measurement with
respect to an accepted value is 5%.

Roger 

> It is better to say "I am off 5%" than "I am off 2 cm". What is wrong with
> using this percentage error indicator for a single evaluation, as long as
> you say this clearly. Yes, it does not say a lot but it does say something.
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Roger A. Pruitt, PhD
Professor of Physics
Fort Hays State University
Hays, KS  67601
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