In the fields of engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements of aquantity to its actual (true) value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which repeated measurements under unchanged conditions show the same results.[1] Although the two words can be synonymous in colloquial use, they are deliberately contrasted in the context of the scientific method.Accuracy准确度 is the difference between the measured value and the true value of a tested material.Precision精确度 is the repeatability of successive measurements under the same conditions.测量的精密度、准确度和精确度这是人们在测量中常常容易混淆的三个名词,虽然它们都是评价测量结果好坏的,但涵义有较大的差别。1.测量的精密度高,是指偶然误差较小,这时测量数据比较集中,但系统误差的大小并不明确。2.测量的准确度高,是指系统误差较小,这时测量数据的平均值偏离真值较少,但数据分散的情况,即偶然误差的大小不明确。3.测量精确度(也常简称精度)高,是指偶然误差与系统误差都比较小,这时测量数据比较集中在真值附近。