We did an experiment with abysmal accuracy. I'm now writing up my report and would like to meaningfully express the error between calculated and measured values. EXAMPLE calculated T=0.284 measured T = 0.201 I want to express the difference between them as follows: % difference between the two = (1 - 0.201/0.284)(100%) = 29% But as ridiculous as the errors are throughout the experiment, they're not that bad! Take the difference between the two values and then divide by one of the two values? But which one? I know how to take percent error for something like [itex]107.45\pm\0.08[/itex] but this seems to be a different cup of tea.