ASTM_E_2617_-_10.pdf

Designation:E261710Standard Practice forValidation of Empirically Derived Multivariate Calibrations1This standard is issued under the fixed designation E2617;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers requirements for the validation ofempirically derived calibrations(Note 1)such as calibrationsderived by Multiple Linear Regression(MLR),Principal Com-ponent Regression(PCR),Partial Least Squares(PLS),Artifi-cial Neural Networks(ANN),or any other empirical calibra-tion technique whereby a relationship is postulated between aset of variables measured for a given sample under test and oneor more physical,chemical,quality,or membership propertiesapplicable to that sample.NOTE1Empirically derived calibrations are sometimes referred to as“models”or“calibrations.”In the following text,for conciseness,the term“calibration”may be used instead of the full name of the procedure.1.2 This practice does not cover procedures for establishingsaid postulated relationship.1.3 This practice serves as an overview of techniques usedto verify the applicability of an empirically derived multivari-ate calibration to the measurement of a sample under test andto verify equivalence between the properties calculated fromthe empirically derived multivariate calibration and the resultsof an accepted reference method of measurement to withincontrol limits established for the prespecified statistical confi-dence level.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E131 Terminology Relating to Molecular SpectroscopyE1655 Practices for Infrared Multivariate QuantitativeAnalysisE1790 Practice for Near Infrared Qualitative Analysis3.Terminology3.1 For terminology related to molecular spectroscopicmethods,refer to Terminology E131.For terminology relatedto multivariate quantitative modeling refer to Practices E1655.While Practices E1655 is written in the context of multivariatespectroscopic methods,the terminology is also applicable toother multivariate technologies.3.2 Definitions of Terms Specific to This Standard:3.2.1 accuracythe closeness of agreement between a testresult and an accepted reference value.3.2.2 biasthe arithmetic average difference between thereference values and the values produced by the analyticalmethod under test,for a set of samples.3.2.3 detection limitthe lowest level of a property in asample that can be detected,but not necessarily quantified,bythe measurement system.3.2.4 estimatethe constituent concentration,identification,or other property of a sample as determined by the analyticalmethod being validated.3.2.5 initial validationvalidation that is performed whenan analyzer system is initially installed or after major mainte-nance.3.2.6 Negative Fraction Identifiedthe fraction of samplesnot having a particular characteristic that is identified as nothaving that characteristic.3.2.6.1 DiscussionNegative Fraction Identified assumesthat the characteristic that the test measures either is or is notpresent.It is not applicable to tests with multiple possibleoutcomes.3.2.7 ongoing periodic revalidationthe quality assuranceprocess by which,in the case of quantitative calibrations,thebias and precision or,in the case of qualitative calibrations,thePositive Fraction Identified and Negative Fraction Identifiedperformance determined during initial validation are shown tobe sustained.3.2.8 Positive Fraction Identifiedthe fraction of sampleshaving a particular characteristic that is identified as havingthat characteristic.3.2.8.1 DiscussionPositive Fraction Identified assumes1This practice is under the jurisdiction of ASTM Committee E13 on MolecularSpectroscopy and Separation Science and is the direct responsibility of Subcom-mittee E13.11 on Multivariate Analysis.Current edition approved March 1,2010.Published April 2010.Originallyapproved in 2008.Last previous edition approved in 2009 as E2617 09a.DOI:10.1520/E2617-10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 that the characteristic that the test measures either is or is notpresent.It is not applicable to tests with multiple possibleoutcomes.3.2.9 precisionthe closeness of agreement between inde-pendent test results obtained under st