Scientists take scientific measurements carefully in order to ensure their reliability and validity. What is the difference between accuracy and precision in scientific measurements

Both terms are related and they are really important in the science field to measure how successful can be an experiment.

First, the accuracy is the relation to express how close is the value that I measure in an experiment from a real value that it has been already proved.

For example: I measure the volume of a soda can in my lab and I found that this soda can has 235 mL inside but the packing says that has 230 mL. So it means that my measure data it is not accurate.

Thus, the accuracy is important because gives me validity of my designed experiment.

Second, the precision is the relation between my datas and how far are they from each other.

For example: Taking again the example of the soda can, I was in the lab measuring the volume and I made it 3 times. My datas were: 235 mL, 220mL, and, 210 mL. So it means that my measures are far from each other so it is not precise.

Precision is important because gives reliability to the experiment.

There is also mathematical approximations to measure accuracy and precision, the accuracy can be measure finding the error and the precision can be measure by a standard deviation that means how far are my datas from the average.

Accuracy refers to the closeness of a measured value to a standard or known value. Precision is independent of accuracy. You can be very precise but inaccurate.