Measurement

Measurement is the assignment of numbers, according to rules, to physical or mental objects, attributes, traits, constructs, or concepts. The purpose of these [Page 642]numerical assignments is to enable comparisons, assessments, judgments, and evaluations through various mathematical computations and manipulations. These numbers may be obtained via the use of measurement tools or self-reports, or may be based on direct observations or judgments of overt phenomena or behaviors by human observers. Because of the convenience of operations of numbers and the general consensus regarding standard mathematical and statistical rules for comparisons and computations of numbers, measurement is considered a fundamental part of science. Galileo stated that, for the sake of knowledge, we must measure what is measurable and make measurable what cannot be measured.

The measurement of ...