さて、先のブログに続いて、precisionとaccuracyについて、記載しておきます。
McGraw-Hill Machining and Metalworking Handbook (McGraw-Hill Handbooks)からの抜粋です。
Precision
For any measuring device, precision is an indication of how much variation one will observe when one measures the same dimension on the same part using the same measuring device. The terms precision and repeatability are often used interchangeably. The sample standard deviation of multiple measurements taken on the same feature with the same device by the same operator is an indicator of precision. The smaller the standard deviation, the higher is the precision.
Accuracy
Accuracy is an indication of how close the measured dimension is to the true value for that dimension. Note that accuracy and precision are not the same thing. A device can be highly precise but very inaccurate. In other words, it can consistently give the same wrong measurement.
precisionとaccuracyに関して、その核となる違いが、とても明快に書かれています。
“McGraw-Hill Machining and Metalworking Handbook”、私はAmazon Kindle版を持っています。移動中などに、時々読み返しています。
Kindleは複数の書籍を平行して読む（例えば10分ごとに、違う本に浮気する）ことが容易に可能ですので、便利です。