Background and threshold: critical comparison of methods of determination.

  title={Background and threshold: critical comparison of methods of determination.},
  author={Clemens Reimann and Peter Filzmoser and Robert G. Garrett},
  journal={The Science of the total environment},
  volume={346 1-3},
Different procedures to identify data outliers in geochemical data are reviewed and tested. The calculation of [mean+/-2 standard deviation (sdev)] to estimate threshold values dividing background data from anomalies, still used almost 50 years after its introduction, delivers arbitrary estimates. The boxplot, [median+/-2 median absolute deviation (MAD)] and empirical cumulative distribution functions are better suited for assisting in the estimation of threshold values and the range of… CONTINUE READING