Chapter 6: Data Evaluation, Validation, and Quality

Abstract

The term “data” means scientific or technical measurements, values, or facts, which can be represented by numbers or in other ways. These values or facts form the basis of calculations and of technical or scientific decisions. To be more specific, materials data should accurately represent such values as ultimate strength in tension, stiffness in torsion, hardness, and up to 50 or more similar mechanical properties in addition to numerous electrical, electronic, thermal, and other physical properties, corrosion, oxidation, and processing characteristics. Each data value corresponds to a particular loading condition, time of application, and set of values for each of several possible ambient environmental and other parameters. First, however, the material itself needs to be identified unambiguously in terms of its chemical composition, form, heat and other treatment, source, and more. Finally, beyond the mechanical and physical properties, data may be required on the cost of a target material, on its availability, its environmental impacts, and even, perhaps, its aesthetic qualities. Most of these data are numeric values, but they do not stand alone. The mechanical properties, for example, are dependent upon the test methods or predictive mathematical models that were used to determine them.