How Do You Tell The Difference Between Accuracy And Precision?
Often the terms accuracy and precision get used interchangeably. They are, however, in fact two different concepts that one must take into consideration when making measurements. Is your measurement being compared to other measurements made with the same instrument? If the answer is yes then go to step two. If your measurement is being compared to the actual value of what you are measuring then go to step three. If all the measurements made with the same instrument of a single item are all close to one another then the measurements are showing precision. Example: You measure the length of a table four times with a meter stick and get the following measurements. 145.5 cm, 145.4 cm, 145.3 cm, and 145.4 cm. These values are all close to one another and would, therefore, be considered precise. If the measurements made on an object are close to the actual value of that object then the measurements are showing accuracy. Example: If the length of a football field is known to be 100 yards long
