Accuracy and Precision: Definition, Difference with Examples | Physics Video Tutorials

In this video we can talk about the difference between accuracy and precision.
What is accuracy?
Accuracy refers to the closeness of a measured value to a standard or known value.
What is precision?
Precision refers to the closeness of two or more measurements to each other.
Now, we can explain it with 2 different examples. Listen carefully.
A visual example:
Target shooting is an example which explains the difference between accuracy and precision. See the visual. Here, the shots are focused so as to reach the bull’s eye (midpoint), but the bullets have reached only around this point. Hence the shots are
not accurate and also not precise.

Here, all the shots are close to each other but not at the central point. Hence the shots are said to be precise but not accurate.

But in visual, the shots are closer and also at the central point. Hence the shots are both precise and accurate.

A numerical example
The true value of a certain length is near 5.678 cm. In one experiment, using a measuring instrument of resolution 0.1 cm, the measured value is found to be 5.5 cm.

In another experiment using a measuring instrument of greater resolution, say 0.01 cm, the length is found to be 5.38 cm. We find that the first measurement is more accurate as it is closer to the true value, but it has lesser precision. On the contrary, the second measurement is less accurate, but it is more precise.