I really emphasize error analysis, and most of my students have a pretty
good handle on identifying random and systematic errors by the end of
the year.
I do not grade on the accuracy of the results. Instead, I give credit
for results that are consistent with the data, and proper identification
of sources of random and systematic error.
I agree that the word "experimental error" is synonymous with "I made a
mistake" in many students' minds. I, too, frequently use the word
"uncertainty" as a synonym for "error", although I still use "error"
about half of the time. I also explicitly state, many times, that
"error" does not necessarily mean that the experimenter made a mistake.
If a lab group does make a mistake, they should repeat the measurement.
On several occasions, my students have repeated measurements when they
made blunders.
Daniel Crowe
Oklahoma School of Science and Mathematics
Ardmore Regional Center
dcrowe@sotc.org
-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@list1.ucc.nau.edu] On
Behalf Of Spagna Jr., George
Sent: Friday, April 29, 2005 11:16 AM
To: PHYS-L@LISTS.NAU.EDU
Subject: Re: [PHYS-L] Human Error?
I suspect that this pet peeve strikes a familiar note for most of us on
this list. I doubt anyone accepts it, but we all see it. Many possible
origins for its ubiquity have been mentioned, most are probably
contributing.
Another that I've not yet seen mentioned is a grading scheme used in
some courses which rewards students for the precision with which they
recovered the "right" answer. Often it's not even explicit, but takes
the form of "calculate the percentage error relative to the textbook
answer."
I try to avoid the use of the word "error," preferring "uncertainty."
That said, I'm no more successful that others who have already responded
in getting students to stop attributing their experimental uncertainties
to human error. It's better with majors, because we can work with them
for several years; harder with chemistry and biology majors who only
take the introductory sequence from us.
********************************************
"The wise person doesn't give the right
answers, but poses the right questions."
- Claude Levi-Strauss
********************************************
Dr. George Spagna
Chair, Physics Department
Randolph-Macon College
P.O. Box 5005
Ashland, VA 23005-5505