1.1 本实践的目的是提出理解定量测试方法中使用的术语“精度”和“偏差”所需的概念。本规程还描述了表示精度和偏差的方法，并在最后一节中给出了如何为ASTM试验方法编写精度和偏差声明的示例。 1.2 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 “蓝皮书”的A部分 ASTM标准的形式和样式 ，要求所有测试方法包括精度和偏差声明。本实践讨论了这两个概念，并为其在测试方法声明中的使用提供了指导。 4.2 精度- 精度声明允许测试方法的潜在用户从总体上评估测试方法在拟议应用中的可变性方面的有用性。精度声明的目的不是展示可以在每个用户的实验室中精确复制的值。相反，该声明提供了在一个或两个或多个具有合理能力的实验室中使用该方法时，测试结果之间可预期的可变性幅度的指南。有关精度的讨论，请参阅 8.1 . 4.3 偏差- 偏差声明提供了在特定试验条件下由试验方法产生的一组典型试验结果与一组相关的可接受参考值之间关系的指南（见 9.1 ). 4.3.1 偏见的另一个术语是真实性，它具有积极的内涵，即更大的偏见与不太有利的真实性相关。真实性是准确性的系统组成部分。 4.4 准确性- 术语“准确性”，在早期版本的实践中使用 E177 ，包含精度和偏差（参见 9.3 ).

1.1 The purpose of this practice is to present concepts necessary to the understanding of the terms “precision” and “bias” as used in quantitative test methods. This practice also describes methods of expressing precision and bias and, in a final section, gives examples of how statements on precision and bias may be written for ASTM test methods. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 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. 4.2 Precision— 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 8.1 . 4.3 Bias— 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 9.1 ). 4.3.1 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. 4.4 Accuracy— The term “accuracy,” used in earlier editions of Practice E177 , embraces both precision and bias (see 9.3 ).