Difference Between Accuracy and Precision (With Table)

Everyone seems that accuracy and precision are similar but it is not true they are quite different from each other. Both the names are often taken together to measure the validity of the data, but how many of you know the actual difference between them.

Accuracy and precision are the two terms that use to measure the things that are related to science and engineering. In the terms of science and engineering, accuracy and precision give the measurement of statistical data.

Accuracy vs Precision

The main difference between accuracy and precision is that accuracy is the closeness of the measurements of a specific value whereas precision is the closeness of a measurement to each other.  The set of specific data is said to be accurate if the average of the data is close to the true value, on the other hand, precision is the set of values that are on the brink of one another.

Accuracy is the correctness of the measurement value while compared to its true value. It agrees closely with the accepted standard for that measurement. For example, accuracy is likely to determine how the value is close to the actual value of that specific data.

While precision refers to how the measurements are close to each other regardless of whether those measurements are accurate or not. For example, the precision of the experiment or object is how something can be constantly and remain exact. It shows the strict exactness of any object or experiment.

Comparison Table Between Accuracy and Precision

Parameters of ComparisonAccuracyPrecision
DefinitionIt is defined as the correctness of the measurement to its true value.Precision means the strict exactness of the measurement.
FactorsIt has a single factor used for the measurement.It has multiple factors used for the measurement
DegreeIt has a degree of veracity.It has a degree of reproducibility.
Mutual relationshipAccuracy can be precise in most of its cases.Precision may or may not be accurate.
Basis of factorsCorrectness and closenessExactness

What is Accuracy?

Accuracy means measuring the degree of the measurement value to its true value. It is the closeness of the measured value with the actual value of something. Thus, accuracy increases its closer measurement of the object is to the actual measurement of the object.

Accuracy is the measured quantity to the reality and takes the account to the accepted value. It is concerned with systematic error. Let it understand with the example, in a lab where the weight measurement value of the substance is 9.8 kg and the actual value is 10kg, then it is near to the actual value so the measurement is accurate.

When a person tries target shooting and he hits in the middle of the target or near around the middle of the target then that is also the accuracy of the shooting of the target. Accuracy is just the correctness and consistency of the measurement. In rigid terms, it is the faithful measurement and representation of the truth.

Thus, accuracy can be shown in the measurements when the correct statics are used to measure the value.

What is Precision?

The closeness of two or more measurements to each other is known as precision. When the measurement value repeatedly gives the same answer then the value is very precise but it may or may be accurate. The measurement value is strictly exact to one another and it gives the factor of multiple measurements to get the precise value.

Let us understand it with an example, there is a temperature of an object id 45-degree Celsius and the thermometer is showing 45 degrees in all the readings, then the thermometer is accurate and precise. 

when the conditions are kept identical and repeated and using the same measurement process among different instruments and operators and the value is close to the other value known as precision. Thus, it is the degree where repeated measurements of the different instruments are unchanged.

Main Differences Between Accuracy and Precision

Accuracy and precision are the two important factors that help to get the value of the measurements. They help to achieve the desired result by underlying the methods of the measurement, but it is important to know the difference between them:

  1. Both accuracy and precision give the closest result of the measurement to the actual value, but accuracy reflects how the measurement value is close to the known or true value whereas precision reflects how reproducible the measurement value are, even it may or may not be accurate.
  2. Accuracy measures the quantity to reality. It does not speak about quality, on the other hand, precision measures how measurement can be reproduced and it speaks about the quality.
  3. Accuracy requires the single factor of measurement that can be limited to one measurement, on the other hand, precision requires multiple factors of measurement, and multiple measurements are needed to evaluate precision.
  4. The measurement value can be accurate and precise both, on the other hand, precision may or may not be accurate.
  5. Accuracy is the degree of veracity i.e., the closeness to the true value, on the other hand, precision is the degree of reproducibility i.e., in which an instrument or operation repeats its same value.

Conclusion

Accuracy and precision are the two words that are used similarly to get the measurement value but also differ too as the accuracy is the closeness of the value to its actual value whereas precision is the strict exactness of the actual value as the value should be the same as one another by any instrument or operations.

Both are important in terms of science and physics as they give the outcomes that should be error-free. When the outcome is accurate it is not important that it will precise too as the accuracy is not dependent on precision and it is also mentioned that precision will also not be accurate too.

Refrences

  1. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-3984.1971.tb00916.x
  2. https://www.ingentaconnect.com/content/mts/mtsj/2002/00000036/00000002/art00005