Question

What is the difference between accuracy and precision and which is most important to scientific measurement?

Answer 1

Accuracy refers to the closeness of a measured value to a standard or known value. While Precision refers to the closeness of two or more measurements to each other. Accurate Measurements are the most important ones.

Answer 2

Precision is how close a test result when repeated. A precise test will give result like 15, 16, 14, 15 ,16. In precision, the actual value is not examined. You only need to look at the result.The standard deviation should be small.

Accuracy is how close the test results to the standard known value. If the actual value is 10, an accurate test would give 8, 12, 11, 10, 13. In this case, the test is varied but the means of the value is close to 10. The standard deviation might be big.

I would say precision is better. Accuracy can be fixed using calibration. In the example above, if you add (-5) to the value the test will give 10, 11, 9, 10, 11 value which has become near the actual value(the accuracy become higher) but has a smaller standard deviation(the precision is still high).