My students are allowed to use ERROR only when there is a known value to
compare their lab results to. If they attempt to determine the
acceleration due to gravity in the lab, they can report that they found
it to be 9.71 m/s/s an absolute error of 0.10 m/s/s or that they
measured the value to within 1% of the accepted value, or that their
value only had a 1% error.
If there is not an accepted value to compare to, then an uncertanty is
expected on the report.