Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: what good is "percentage error"?




I teach the use of "percentage error" in my intro college physics labs
(though I use the term "percent error" because it seems grammatically correct).
I believe there is certainly SOME validity to using this measurement, which is
after all just the fractional error multiplied by 100; in many (though
obviously not all) cases it gives us useful information about the results of a
measurement.
Case in point: suppose I sent one group out to measure the length of a
football field, and another group to measure the diameter of a penny. If they
both came back with measurements that showed an error of five cm, I don't think
it's helpful to conclude that there was equivalent accuracy in the two
measurements.
While there are many caveats to the use of percent error (i.e., what
about measurements whose accepted value is zero?), it seems to me that it does
add value to our understanding.

Regards, PRB


^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| Patrick R. Briggs |
| Dept. of Physics |
| The Citadel |
| Charleston, SC 29409 |
| (803) 953-6948 |
| internet: briggsp@citadel.edu |
| http://www.citadel.edu/citadel/otherserv/phys/briggs.html |
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^