Difference Between Accuracy and Precision

Accuracy vs Precision

The terms accuracy and precision are often encountered in the fields of engineering, physics, and industry. Accuracy of a measurement means getting a value that is close to the actual answer. Precision on the other hand refers to reproducibility of this result that is you get same result every time you try. Even this clear cut demarcation does not stop people from relating these two concepts and talk of them in similar terms. However, accuracy and precision are as different as cheese and chalk which will be clear to the readers after reading this article.

Have you ever played darting as a kid? Yes, the same game where there is a circular target that is pinned on a wall and kids try to hit the centre of the target that fetches them maximum points. Now if a kid hits the centre, he is said to be accurate and if he happens to hit the centre regularly, he is also precise, which is to say that he is hitting bull’s eye all the time.

If a person is just less than 6 feet in height, he would not like to be so accurate as to say he is 5 feet 11 and three quarters of an inch in height which would also look troublesome for anyone to understand. So he can sacrifice accuracy in favor of a number that is easier to speak and also to remember. Had you used millimeters to describe your height, you could have done it more accurately.

Now that you know the difference between accuracy and precision, you must also know that the results of calculation or a measurement can be accurate but not precise, precise but not accurate, neither, or both. Any measurement system is valid only if it is both accurate as well as precise.

In brief:

• The concepts of accuracy and precision are encountered in measurement in physics and in industry

• Accuracy refers to closeness of a measurement to its actual or real value while precision refers to the regularity of obtaining the same result frequently.

• It is possible to be accurate yet not precise. Its converse is also true.