Hello,

I am a bit confused about appellation and calculation of validation parameters.

Am I right that Accuracy is qualitative (not quantitative) parameter and is a combination of Trueness and Precision?

Am I right with calculation of Trueness?

ref/x_{avg}

where *ref* is reference value, *x*_{avg} is average (but sometimes I read median?)

And Precision depends on systematic error and is calculated

s/x_{avg}

where *s* is standard deviation based on a sample (or the entire population?), *x*_{avg} is average

Thanks for every answer