Indentation hardness
Hardness measurements quantify the resistance of a material to plastic deformation. Indentation hardness tests compose the majority of processes used to determine material hardness, and can be divided into two classes: "microindentation" and "macroindentation" tests. Microindentation tests typically have forces less than . Hardness, however, cannot be considered to be a fundamental material property. Classical hardness testing usually creates a number which can be used to provide a relative idea of material properties. As such, hardness can only offer a comparative idea of the material's resistance to plastic deformation since different hardness techniques have different scales.
Hardiness (psychological)
There are several instrument developed to measure hardiness, the most frequently used being the Personal Views Survey, the Dispositional Resilience Scale, and the Cognitive Hardiness Scale. In addition to these, other scales based on hardiness theory have been designed to measure the construct in specific contexts and in special populations, such as for example parental grief and among the chronically ill.