Precision
Precision refers to how consistently a tool or process can produce similar results under the same conditions. It is about repeatability and reliability, not necessarily how close these results are to the true or intended value.
If we weigh something five times and each time the scale reads exactly 4.6 kg, our measurements are precise. They consistently show the same result.
Precision can be further broken down into two aspects:
- Repeatability
- Reproducibility
Repeatability
Repeatability refers to the variation in measurements taken by a single instrument or individual under unchanged conditions over a short period. For example, if we measure the length of a table several times in one sitting and get almost identical results each time, our measurements show good repeatability.
Reproducibility
Reproducibility is a measure of whether a measurement can be duplicated by different people, using different instruments, over extended periods. For example, if several different workers use different tape measures to size the same table on different days and their measurements are very close, the method is reproducible.
Precision Formula
To calculate precision, we use the formula for standard deviation, which shows how much the values in a set deviate from the average. Its formula is given by :
Standard Deviation (Precision) = √(∑(Measurement −Mean)2/ Number of measurements)
A smaller standard deviation indicates that the measurements are closely clustered around the mean, which means higher precision.
Accuracy and Precision in Measurement
Accuracy means how close a measurement comes to the true value while precision refers to how consistently one can repeat a measurement. Every measurement contains some uncertainty in them. It may be due to limitations in measurement tools, observer variation, or environmental factors. This affects both the accuracy and precision of measurements. In this article, we are going to learn about accuracy and precision in detail, along with their examples and differences.
Table of Content
- Accuracy
- Precision
- Accuracy and Precision Examples
- Difference between Accuracy and Precision
- Solved Examples on Accuracy and Precision
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