| Definition |
Precision refers to how consistent or repeatable measurements are, regardless of how close they are to the true value. |
Accuracy refers to how close a measured value is to the true or accepted value. |
| Focus |
Focuses on the repeatability of measurements. |
Focuses on how close the measurements are to the true value. |
| Measurement Consistency |
Measurements are consistent and close to each other, but not necessarily near the true value. |
Measurements are close to the true value, but not necessarily consistent. |
| Example |
A dartboard example: If a person throws five darts, and they all land in the same spot but far from the bullseye, they are precise but not accurate. |
If the five darts land near the bullseye (true value), but not necessarily in the same spot, they are accurate but not necessarily precise. |
| Error Type |
The error is random (fluctuating with each measurement), but the readings are still tightly grouped together. |
The error is systematic (consistently deviates from the true value). |
| Impact of Repeated Measurements |
Repeated measurements will give very similar results, even if those results deviate from the true value. |
Repeated measurements will vary, but the average will be close to the true value. |
| Use Case |
Precision is important when consistency in measurements is critical (e.g., manufacturing processes). |
Accuracy is important when the correctness of measurements is critical (e.g., scientific experiments). |