ISO 21748:2017提供了以下指南: -使用根据ISO 5725-2进行的研究获得的数据评估测量不确定度，以及 -将合作研究结果与使用不确定度传播形式原理获得的测量不确定度（MU）进行比较（见第14条）。 ISO 5725-3为中等精度的研究提供了额外的模型。然而，虽然相同的一般方法可应用于此类扩展模型的使用，但使用这些模型的不确定性评估不包含在本文件中。 ISO 21748:2017适用于所有测量和试验领域，其中必须确定与结果相关的不确定度。 ISO 21748:2017没有描述在缺乏再现性数据的情况下重复性数据的应用。 ISO 21748:2017假设通过将数值校正作为测量方法的一部分，或通过调查和消除影响原因，对公认的、不可忽略的系统影响进行校正。 本文件中的建议主要用于指导。人们认识到，虽然所提出的建议确实构成了一种有效的方法来评估许多目的的不确定性，但也可以采用其他合适的方法。 一般而言，本文件中提及的测量结果、方法和过程通常也适用于测试结果、方法和过程。

ISO 21748:2017 gives guidance for - evaluation of measurement uncertainties using data obtained from studies conducted in accordance with ISO 5725？2, and - comparison of collaborative study results with measurement uncertainty (MU) obtained using formal principles of uncertainty propagation (see Clause 14). ISO 5725？3 provides additional models for studies of intermediate precision. However, while the same general approach may be applied to the use of such extended models, uncertainty evaluation using these models is not incorporated in this document. ISO 21748:2017 is applicable to all measurement and test fields where an uncertainty associated with a result has to be determined. ISO 21748:2017 does not describe the application of repeatability data in the absence of reproducibility data. ISO 21748:2017 assumes that recognized, non-negligible systematic effects are corrected, either by applying a numerical correction as part of the method of measurement, or by investigation and removal of the cause of the effect. The recommendations in this document are primarily for guidance. It is recognized that while the recommendations presented do form a valid approach to the evaluation of uncertainty for many purposes, it is also possible to adopt other suitable approaches. In general, references to measurement results, methods and processes in this document are normally understood to apply also to testing results, methods and processes.