Accuracy and precision

thumb|upright|Four measuring devices having metric calibrations Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind. The scope and application of measurement are dependent on the context and discipline. In natural sciences and engineering, measurements do not apply to nominal properties of objects or events, which is consistent with the guidelines of the Internat

measures of observational error

In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, a device generating the quantity to be measured such as a voltage, a sound tone, or a physical artifact, such as a meter ruler.

statistical property quantifying how much a collection of data is spread out

difference between a measured quantity value and a reference quantity value

an intuitive measure of a weapon system's precision

statistical measures of the performance of a binary classification test

expected value of a statistical estimator's error

any systematic tendency which causes statistical findings to differ from reality

distance between independent measurements, or the physical dimension that represents a pixel of an image