What is percent error?
Percent error compares an experimental measurement with an accepted value. It is often used in science labs to judge how accurate a result was.
Percent error vs percent difference
Percent error needs a known true value. Percent difference is used when comparing two measured values where neither one is treated as the correct answer.
How to reduce experimental error
Repeat measurements, calibrate equipment, control variables, use appropriate significant figures, and check for systematic bias in the method.