Difference Between Accuracy and Precision

What Is the Difference Between Accuracy and Precision?

https://www.thoughtco.com/difference-between-accuracy-and-precision-609328

Key Takeaways: Accuracy Versus Precision

• Accuracy is how close a value is to its true value. An example would be how close an arrow gets to the bullseye center.
• Precision is how repeatable a measurement is. An example would be how close a second arrow is to the first one (regardless of whether either is near the mark).
• Percent error is used to assess whether sufficiently accurate and precise.

You can think of accuracy and precision in terms of hitting a bullseye. Accurately hitting the target means you are close to the center of the target, even if all of the marks are on different sides of the center. Precisely hitting a target means all the hits are closely spaced, even if they are very far from the center of the target. Measurements which are both precise and accurate are repeatable and very near true values.

Mnemonic To Memorize the Difference

An easy way to remember the difference between accuracy and precision is:

 

• ACcurate is Correct. (or Close to real value)
• PRecise is Repeating. (or Repeatable)

机器学习中的Bias(偏差)，和Variance(方差)有什么区别和联系？

https://www.zhihu.com/question/27068705