Editing Measurement (section)

== Methodology ==
The measurement of a property may be categorized by the following criteria: [[level of measurement|type]], [[magnitude (mathematics)|magnitude]], [[units of measurement|unit]], and [[uncertainty]].{{citation needed|date=July 2015}} They enable unambiguous comparisons between measurements.
* The ''level'' of measurement is a taxonomy for the methodological character of a comparison. For example, two states of a property may be compared by ratio, difference, or ordinal preference. The type is commonly not explicitly expressed, but implicit in the definition of a measurement procedure.
* The ''magnitude'' is the numerical value of the characterization, usually obtained with a suitably chosen [[measuring instrument]].
* A ''unit'' assigns a mathematical weighting factor to the magnitude that is derived as a ratio to the property of an artifact used as standard or a natural physical quantity.
* An ''uncertainty'' represents the [[observational error|random and systemic errors]] of the measurement procedure; it indicates a confidence level in the measurement. Errors are evaluated by methodically repeating measurements and considering the [[accuracy and precision]] of the measuring instrument.