1.1 This document amplifies the general principles to be observed in designing experiments for the numerical estimation of the precision of measurement methods by means of a collaborative interlaboratory experiment; provides a detailed practical description of the basic method for routine use in estimating the precision of measurement methods; provides guidance to all personnel concerned with designing, performing or analysing the results of the tests for estimating precision. NOTE – Modifications to this basic method for particular purposes are given in other parts of ISO 5725. Annex C provides practical examples of estimating the precision of measurement methods by experiment. 1.2 This document is concerned exclusively with measurement methods which yield measurements on a continuous scale and give a single value as the test result, although this single value may be the outcome of a calculation from a set of observations. 1.3 It assumes that in the design and performance of the precision experiment, all the principles as laid down in ISO 5725-1 have been observed. The basic method uses the same number of test results in each laboratory, with each laboratory analysing the same levels of test sample; i.e. a balanced uniform-level experiment. The basic method applies to procedures that have been standardized and are in regular use in a number of laboratories.