ASTM E2935-21

4.2.1Means equivalenceis concerned with a potential shift in the mean test result in either direction due to a modification in the testing process. Test results are generated under repeatability conditions by the modified and current testing processes on the same material, and the difference in their mean test results is evaluated.

4.2.2Slope equivalenceevaluates the slope of the linear statistical relationship between the test results from the two testing procedures. If the slope is equivalent to the value one (1), then the two testing processes meet slope equivalence.

4.2.3Range equivalenceevaluates the differences in means over a selected wider range of test results and the experiment uses materials that cover that range. The combination of slope equivalence and means equivalence defines range equivalence.

4.2.4Non-inferiorityis concerned with a difference only in the direction of an inferior outcome in a performance characteristic of the modified testing procedure versus the current testing procedure. Non-inferiority may involve the comparisons of means, standard deviations, or other statistical parameters.

4.3.1The 4.3.2The 1.1This practice provides statistical methodology for conducting equivalence studies on numerical data from two sources of test results to determine if their true means, variances, or other parameters differ by no more than predetermined limits.

1.2Applications include (1) equivalence studies for bias against an accepted reference value, (2) determining means equivalence of two test methods, test apparatus, instruments, reagent sources, or operators within a laboratory or equivalence of two laboratories in a method transfer, and (3) determining non-inferiority of a modified test procedure versus a current test procedure with respect to a performance characteristic.

1.3The guidance in this standard applies to experiments conducted either on a single material at a given level of the test result or on multiple materials covering a selected range of test results.

1.4Guidance is given for determining the amount of data required for an equivalence study. The control of risks associated with the equivalence decision is discussed.

1.5The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6This 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.

1.7This 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.