ASTM E177-08
Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods

Standard No.
ASTM E177-08
Release Date
2008
Published By
American Society for Testing and Materials (ASTM)
Status
Replace By
ASTM E177-10
Latest
ASTM E177-20
Scope

Part A of the “Blue Book,” Form and Style for ASTM Standards, requires that all test methods include statements of precision and bias. This practice discusses these two concepts and provides guidance for their use in statements about test methods.

Precision8212;A statement of precision allows potential users of a test method to assess in general terms the test method''s usefulness with respect to variability in proposed applications. A statement of precision is not intended to exhibit values that can be exactly duplicated in every user''s laboratory. Instead, the statement provides guidelines as to the magnitude of variability that can be expected between test results when the method is used in one, or in two or more, reasonably competent laboratories. For a discussion of precision, see Section 15.

Bias8212;A statement of bias furnishes guidelines on the relationship between a set of typical test results produced by the test method under specific test conditions and a related set of accepted reference values (see Section 16).

An alternative term for bias is trueness, which has a positive connotation, in that greater bias is associated with less favorable trueness. Trueness is the systematic component of accuracy.

Accuracy8212;The term “accuracy,” used in earlier editions of Practice E 177, embraces both precision and bias (see Section 17 and Note 3).

A Table of Contents is shown below, listing the concepts in this standard.

TABLE OF CONTENTSSection
GENERAL CONCEPTS
Test Method 5
Measurement Terminology 6
SOURCES OF VARIABILITY
Experimental Realization of a Test Method 7
Operator 8
Apparatus 9
Environment 10
Sample 11
Time 12
STATISTICAL CONCEPTS
Accepted Reference Value 13
Statistical Control 14
Precision 15
Bias 16
Accuracy 17
Variation of Precision and Bias with Material 18
Variation of Precision and Bias ......<......

ASTM E177-08 history

  • 2020 ASTM E177-20 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2019 ASTM E177-19 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2014 ASTM E177-14 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2013 ASTM E177-13 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2010 ASTM E177-10 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2008 ASTM E177-08 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2006 ASTM E177-06b Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2006 ASTM E177-06a Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2006 ASTM E177-06 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2004 ASTM E177-04e1 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 2004 ASTM E177-04 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 1990 ASTM E177-90a(2002) Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
  • 1996 ASTM E177-90a(1996) Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods


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