Target practice: a BMET's guide to accuracy, precision and resolution.

1. Accuracy quantifies the uncertainty in the measurements made with an instrument. 2. Precision quantifies the expected scatter or spread of a group of repeated measurements of a fixed quantity. 3. Resolution is the smallest change or increment in the measured quantity that the measuring instrument can detect with certainty. Words, words, words. If you're like most of us, you'll find a picture more memorable than a list of definitions. Accuracy, precision, and resolution are a simple as taking aim at a bull's eye and understanding your results.