2017 | AFC ACCOMPLISHMENTS 95 respectively, provided a good descrip- tion of the distribution of proportional limit stress data (Figure 3). The study also led to the development of the precision statement for the ASTM C1773-13 standard.The preci- sion statementwill be incorporated in the next revision of the ASTM standard The precision statement conveys the important information about the repeatability and reproducibility of the test results. Repeatability refers to the accuracy and random variability of the results obtained with the same method on identical test items in the same laboratory by the same operator using the same equipment within short intervals of time within a single laboratory. Reproducibility refers to the accuracy and random variability associated with successive measurements of the same property carried out by operators working in different laboratories, each obtaining single results on identical test material when applying the same methodThus, precision of a test method provides an estimate of the variation the user of the test method can expect, which in turn reflects the utility of the standard test method. Figure 3. An example analysis for inter-laboratory round-robin test results – statistics for proportional limit tensile stress are compared across laboratories using lognormal distribution-based 95% confidence bounds.