Importance of Sampling to Overall Uncertainty in an Analysis

The overall variance in an analysis, s2, is the sum of the variances arising from the method, (smeth)2, and the variance due to sampling, (ssamp)2.

 s2 = (smeth)2 +  (ssamp)2

The blue curve in this figure shows the method’s contribution to the overall variance, s2, as a function of the relative magnitude of the standard deviation in sampling, ssamp, and the method’s standard deviation, smeth. The dashed red line shows that the method accounts for only 10% of the overall variance when ssamp = 3 × smeth. Understanding the relative importance of potential sources of indeterminate error is important when considering how to improve the overall precision of the analysis.

Figure7.2

About Author

This entry was posted in Illustration and tagged , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *