When it comes to the matter of measuring an item or substance, the topic of discussion turns from the item to the accuracy or precision of the measurement. Both these terms are used interchangeably quite often, but they are not the same.
Table of Content
- What is Accuracy?
- What is Precision?
- Image for accuracy and precision
- Difference Between Accuracy And Precision
- FAQs on accuracy and precision
What is Accuracy?
Accuracy would be referred to as the level of correctness of measurement when compared to its true value.
What is Precision?
Precision, on the other hand, Precision refers to the closeness of two or more measurements to each other.
In simple terms, precision is the term used to see how reliable and consistent the measurement of the experiment is. While accuracy on the other hand checks the closeness of the experiment measurement with the ideal or accepted value.
An ideal analogy to remember accuracy and precision is to remember a basketball player trying to shoot at the baskets where if the player would shoot with the most accuracy the ball would land either close or into the basket. If the player tried to shoot with precision, the ball would fall in the exact location which would be either close or not close to the basket. A right player would be accurate and precise at the same time by shooting the ball always into the basket.
For example, if in lab you obtain a weight measurement of 3.2 kg for a given substance, but the actual or known weight is 10 kg, then your measurement is not accurate. In this case, your measurement is not close to the known value.
Using the example above, if you weigh a given substance five times, and get 3.2 kg each time, then your measurement is very precise. Precision is independent of accuracy. You can be very precise but inaccurate, as described above. You can also be accurate but imprecise.
For example, if on average, your measurements for a given substance are close to the known value, but the measurements are far from each other, then you have accuracy without precision.’
Difference Between Accuracy And Precision
|Definition||It could be defined as the level of correctness of a measurement to its true value.||It could be defined as the sharp exactness of a measurement.|
|Measurement Method||Has one factor used for measuring.||Has multiple factors for measurement.|
|Mutual Relationship||Accurate items have to be precise in most cases.||Precise items may or may not be accurate.|
The points mentioned below are an indication of how terms like accuracy and precision vary from one another despite being used by people interchangeably on most occasions. For more information on topics like uncertainty in measurement, keep visiting BYJU’S.