ASTM_E_1402_-_13.pdf

Designation:E140213An American National StandardStandard Guide forSampling Design1This standard is issued under the fixed designation E1402;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 guide defines terms and introduces basic methodsfor probability sampling of discrete populations,areas,andbulk materials.It provides an overview of common probabilitysampling methods employed by users of ASTM standards.1.2 Sampling may be done for the purpose of estimation,ofcomparison between parts of a sampled population,or foracceptance of lots.Sampling is also used for the purpose ofauditing information obtained from complete enumeration ofthe population.1.3 No system of units is specified in this standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.2.Referenced Documents2.1 ASTM Standards:2D7430 Practice for Mechanical Sampling of CoalE105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE141 Practice for Acceptance of Evidence Based on theResults of Probability SamplingE456 Terminology Relating to Quality and Statistics3.Terminology3.1 DefinitionsFor a more extensive list of statisticalterms,refer to Terminology E456.3.1.1 area sampling,nprobability sampling in which amap,rather than a tabulation of sampling units,serves as thesampling frame.3.1.1.1 DiscussionArea sampling units are segments ofland area and are listed by addresses on the frame prior to theiractual delineation on the ground so that only the randomlyselected ones need to be exactly identified.3.1.2 bulk sampling,nsampling to prepare a portion of amass of material that is representative of the whole.3.1.3 cluster sampling,nsampling in which the samplingunit consists of a group of subunits,all of which are measuredfor sampled clusters.3.1.4 frame,na list,compiled for sampling purposes,which designates all of the sampling units(items or groups)ofa population or universe to be considered in a specific study.3.1.5 multi-stage sampling,nsampling in which thesample is selected by stages,the sampling units at each stagebeing selected from subunits of the larger sampling unitschosen at the previous stage.3.1.5.1 DiscussionThe sampling unit for the first stage isthe primary sampling unit.In multi-stage sampling,this unit isfurther subdivided.The second stage unit is called the second-ary sampling unit.A third stage unit is called a tertiarysampling unit.The final sample is the set of all last stagesampling units that are obtained.As an example of sampling alot of packaged product,the cartons of a lot could be theprimary units,packages within the carton could be secondaryunits,and items within the packages could be the third-stageunits.3.1.6 nested sampling,nsame as multi-stage sampling.3.1.7 primary sampling unit,PSU,nthe item,element,increment,segment or cluster selected at the first stage of theselection procedure from a population or universe.3.1.8 probability proportional to size sampling,PPS,nprobability sampling in which the probabilities of selectionof sampling units are proportional,or nearly proportional,to aquantity(the“size”)that is known for all sampling units.3.1.9 probability sample,na sample in which the sam-pling units are selected by a chance process such that aspecified probability of selection can be attached to eachpossible sample that can be selected.3.1.10 proportional sampling,na method of selection instratified sampling such that the proportions of the samplingunits(usually,PSUs)selected for the sample from each stratumare equal.3.1.11 quota sampling,na method of selection similar tostratified sampling in which the numbers of units to be selected1This guide is under the jurisdiction of ASTM Committee E11 on Quality andStatistics and is the direct responsibility of Subcommittee E11.10 on Sampling/Statistics.Current edition approved Aug.1,2013.Published August 2013.Originallyapproved in 2008.Last previous edition approved in 2008 as E1402 081.DOI:10.1520/E1402-13.2For 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 from each stratum is specified and the selection is done bytrained enumerators but is not a probability sample.3.1.12 sampling fraction,f,nthe ratio of the number ofsampling units selected for the sample to the number ofsampling units available.3.1.13 sampling unit,nan item,group of items,or seg-ment of mat