Question

How can precision be measured?

Answer 1

To know the measurement process of precision, we should go through the whole concept of accuracy and the precision. It may be measured in the standard deviation. We will discuss more about the precision.

Complete answer:
As we should know, accuracy refers to the closeness of a measurement to the TRUE value; whereas precision refers to the repeatability of a measurement. Precise measurements may be inaccurate due to some systematic error, and accurate measurements may be imprecise given the scatter, i.e. the range of a series of measurements.
You will be introduced to a range of ways of dealing with error in your analytical chemistry text. This will also include formal definitions of ${\sigma _d}$ , standard deviation.
Precision is a description of random errors, a measure of statistical variability.
In simpler terms, given a set of data points from repeated measurements of the same quantity, the set can be said to be accurate if their average is close to the true value of the quantity being measured, while the set can be said to be precise if the values are close to each other. In the first, more common definition of "accuracy" above, the two concepts are independent of each other, so a particular set of data can be said to be either accurate, or precise, or both, or neither.

Note:
Precision can be seen as a measure of quality, and recall as a measure of quantity. Higher precision means that an algorithm returns more relevant results than irrelevant ones, and high recall means that an algorithm returns most of the relevant results (whether or not irrelevant ones are also returned).