准确度与精密度的区别

准确度(Accuracy)与精密度(Precision)的区别

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. Although the two

words can be synonymous in colloquial use, they are deliberately contrasted in the

context of the scientific method.

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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。

Accuracy

Accuracy is how close a measured value is to the actual (true) value.

Precision

Precision is how close the measured values are to each other.

准确度（Accuracy）：指在一定实验条件下多次测定的平均值与真值相符合的程度，以误差来表示。它用来表示系统误差的大小。

精密度（Precision）：是指多次重复测定同一量时各测定值之间彼此相符合的程度。表征测定过程中随机误差的大小。

（精密度高是指重复性好repeatability，描述仪器本身的性能用precision；最对比实验得到的结果用准确度accuracy，对比仪器的值可看作真值；一般实验结果给出的是标准偏差standard deviation，用不确定度uncertainty表示）

精确度=准确度+精密度

可用下图表示：

Accuracy and precision in binary classification

"Accuracy" is also used as a statistical measure of how well a binary

classification test correctly identifies or excludes a condition.

That is, the accuracy is the proportion of true results (both true

positives and true negatives) in the population. It is a parameter of the

test

On the other hand, precision is defined as the proportion of the true

positives against all the positive results (both true positives and false

positives)