There is always a confusion between accuracy and precision, whether they are same or different. Let’s see this in detail.
Accuracy v/s Precision
Accuracy refers to how close a measured value is to the true value.
In measurements, we have, measured value and the true Value.
Measured value is the value obtained from a measurement of a physical quantity using an instrument or a measuring device. It is the istatenous value shown by the meter. While, true value refers to the exact or correct value of a quantity being measured. In practice, if we take so many readings and take an average of all the readings in that case the value which is come out that is nothing but the True Value.
You can watch the quick video below or read along.
What is Accuracy?
To avoid the error or to minimize the error what is needed that the measured value should approximately equal or nearly equal to the True Value.
You can refer this article: Are Measured Value And True Value The Same?
For better accuracy measured value should be nearly eqaul to the true value.
For example, if you are measuring a voltage of 5V with voltmeter then meter showing 4.8V would be more accurate that the one showing 4.7V.
What is Precision?
Precision, on the other hand, refers to how consistent and reproducible a measurement is.
If we take so many readings, that readings should nearly equal to one another. More closer the reading are, more will be the precision.
For better precise the requirement is, the readings of that meter should approximately equal or nearly equal to one another.
For example you can say the first set of readings let us say that is 5, 5.1 and 5.2. And the second set of readings will be let us say it is 5, 4.9 or you can say 5.5.
In this first meter readings, readings are approximately equal to one. But in the second set of readings the readings will vary so far.
So we can say that the first meter is more precise than the second meter.
To summarize, accuracy is the degree of closeness to the true value, while precision is the degree of consistency between measurements. A measurement can be accurate but not precise, precise but not accurate, or both accurate and precise.
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