What's the difference between accuracy and precision? They are not the same, and the difference is important. "Accurate" data gives an impression that closely matches the real thing it is measuring. "Precise" data is measured in a way that gives highly specific measures. For example, if you measure your height with a measuring tape that marks to the 100th of a centimeter, you will get a precise measure, but if use the tape wrong (for example, not starting the tape from the floor) your measure will be inaccurate. Data can be precise but totally inaccurate, and we often pay too much attention to precision and too little to accuracy.