Taking and Testing GOODSamples: A Systematic Approach for Representative Sampling from Field to Test Portion


  • Nancy J. Thiex Thiex Laboratory Solutions LLC 46747 214th St., Brookings, SD 57006
  • Charles A. Ramsey EnviroStat, Inc. P.O. Box 657, Windsor, CO 80550




Sampling, sample, primary sample, laboratory sample, sample preparation, theory of sampling, sample quality criteria, global estimation error, representative sample


  • The following manuscript provides a brief introduction to a systematic approach for representative sampling from field to test portion
  • Sampling from field to test portion is a single measurement process
  • Error is introduced during each mass reduction stage
  • Error propagates as the square root of the sum of squares, so the largest error components have a proportionately greater impact
  • A representative sample must be correct (unbiased) and have suciently small imprecision
  • The systematic approach for developing a sampling protocol is based on two key inputs: sample quality criteria (SQC) and material properties
  • This approach requires knowledge of the total error in the measurement process (global estimation error or GEE), from primary sampling through final measurement
  • Error is estimated through quality control events
  • If the GEE meets the requirements of the SQC, a confident inference can be made
  • GOODSamples can be a valuable tool for the forage and feed communities to evaluate current practices and to develop new protocols
https://doi.org/10.21423/jrs-v04n02p001 (DOI assigned 7/3/2019)


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