ASTM E1488-12e1
(Guide)Standard Guide for Statistical Procedures to Use in Developing and Applying Test Methods
Standard Guide for Statistical Procedures to Use in Developing and Applying Test Methods
SIGNIFICANCE AND USE
4.1 The creation of a standardized test method generally follows a series of steps from inception to approval and ongoing use. In all such stages there are questions of how well the test method performs.
4.1.1 Assessments of a new or existing test method generally involve statistical planning and analysis. This standard recommends what approaches may be taken and indicates which standards may be used to perform such assessments.
4.2 This standard introduces a series of phases which are recommended to be considered during the life cycle of a test method as depicted in Fig. 1. These begin with a design phase where the standard is initially prepared. A development phase involves a variety of experiments that allow further refinement and understanding of how the test method performs within a laboratory. In an evaluation phase the test method is then examined by way of interlaboratory studies resulting in precision and bias statistics which are published in the standard. Finally, the test method is subject to a monitoring phase.
4.3 All ASTM test methods are required to include statements on precision and bias.3
4.4 Since ASTM began to require all test methods to have precision and bias statements that are based on interlaboratory test methods, there has been increased concern regarding what statistical experiments and procedures to use during the development of the test methods. Although there exists a wide range of statistical procedures, there is a small group of generally accepted techniques that are beneficial to follow. This guide is designed to provide a brief overview of these procedures and to suggest an appropriate sequence of carrying out these procedures.
4.5 Statistical procedures often result in interpretations that are not absolutes. Sometimes the information obtained may be inadequate or incomplete, which may lead to additional questions and the need for further experimentation. Information outside the data is also important in establishing...
SCOPE
1.1 This guide identifies statistical procedures for use in developing new test methods or revising or evaluating existing test methods, or both.
1.2 This guide also cites statistical procedures especially useful in the application of test methods.
General Information
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Standards Content (Sample)
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Designation: E1488 − 12 An American National Standard
Standard Guide for
Statistical Procedures to Use in Developing and Applying
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Test Methods
This standard is issued under the fixed designation E1488; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
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ε NOTE—Editorial corrections were made to 3.1.25 in April 2013.
1. Scope E2587 Practice for Use of Control Charts in Statistical
Process Control
1.1 This guide identifies statistical procedures for use in
E2655 Guide for Reporting Uncertainty of Test Results and
developing new test methods or revising or evaluating existing
Use of the Term Measurement Uncertainty inASTM Test
test methods, or both.
Methods
1.2 This guide also cites statistical procedures especially
useful in the application of test methods.
3. Terminology
1.3 This international standard was developed in accor-
3.1 Definitions—For a more extensive list of terms in E11
dance with internationally recognized principles on standard-
standards, see Terminology E456.
ization established in the Decision on Principles for the
3.1.1 bias, n—the difference between the expectation of the
Development of International Standards, Guides and Recom-
test results and an accepted reference value. E177
mendations issued by the World Trade Organization Technical
3.1.1.1 Discussion—Statistical procedures include the sam-
Barriers to Trade (TBT) Committee.
plingconsiderationsortheexperimentdesignforthecollection
of data, or both, and the numerical and graphical approaches to
2. Referenced Documents
summarize and analyze the collected data.
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2.1 ASTM Standards:
3.1.2 coeffıcient of variation, CV, n—for a nonnegative
E177 Practice for Use of the Terms Precision and Bias in
characteristic, the ratio of the standard deviation to the mean
ASTM Test Methods
for a population or sample. E2586
E178 Practice for Dealing With Outlying Observations
3.1.3 component of variance, n—a part of a total variance
E456 Terminology Relating to Quality and Statistics
identified with a specified source of variability.
E691 Practice for Conducting an Interlaboratory Study to
3.1.4 control chart, n—chart on which are plotted a statis-
Determine the Precision of a Test Method
ticalmeasureofasubgroupversustimeofsamplingalongwith
E1169 Practice for Conducting Ruggedness Tests
limits based on the statistical distribution of that measure so as
E1402 Guide for Sampling Design
to indicate how much common, or chance, cause variation is
E2282 Guide for Defining the Test Result of a Test Method
inherent in the process or product. E2587
E2489 Practice for Statistical Analysis of One-Sample and
Two-SampleInterlaboratoryProficiencyTestingPrograms 3.1.5 observation, n—the process of obtaining information
E2554 Practice for Estimating and Monitoring the Uncer- regarding the presence or absence of an attribute of a test
tainty of Test Results of a Test Method Using Control specimen, or of making a reading on a characteristic or
Chart Techniques dimension of a test specimen. E2282
E2586 Practice for Calculating and Using Basic Statistics
3.1.6 observed value, n—the value obtained by making an
observation. E2282
3.1.7 precision, n—the closeness of agreement between
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This guide is under the jurisdiction of ASTM Committee E11 on Quality and
independent test results obtained under stipulated conditions.
Statistics and is the direct responsibility of Subcommittee E11.20 on Test Method
Evaluation and Quality Control. E177
Current edition approved Aug. 1, 2012. Published September 2012. Originally
3.1.8 proficiency testing, n—determination of laboratory
approved in 1992. Last previous edition approved in 2009 as E1488 – 09. DOI:
testing performance by means of interlaboratory comparisons.
10.1520/E1488-12E01.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
E2489
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.9 repeatability, n—precision under repeatability condi-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tions. E177
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E1488 − 12
3.1.10 repeatability conditions, n—conditions where inde- ongoing use. In all such stages there are questions of how well
pendent test results are obtained with the same method on the test method performs.
identical test items in the same laboratory by the same operator 4.1.1 Assessments of a new or existing test method gener-
using the same equipm
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