- Precision is the degree to which repeated (or reproducible) measurements under unchanged conditions show the same results.
- Precision is the level of agreement of a particular measurement with itself when it is repeated.
- Accuracy is the proximity of measurement results to the true value;
- Accuracy is the fact of being correct and without any mistakes:
Assume that Systolic BP is 120 and is measured five times
- Precise Accurate : 120,120,120,120,120
- Not precise Accurate : 118,119,120,121,122
- Precise Not accurate : 130,130,130,130,130
- Not Precise Not Accurate : 120, 125, 130, 135, 140
Precision : Zero or Low Standard Deviation