[data quality]
The degree to which the measured value of some quantity is estimated to vary from its true value. Uncertainty can arise from a variety of sources, including limitations to the precision or accuracy of a measuring instrument or system; measurement error; the integration of data that uses different scales or that describes phenomena differently; conflicting representations of the same phenomena; the variable, unquantifiable, or indefinite nature of the phenomena being measured; or the limits of human knowledge. Uncertainty is often used to describe the degree of accuracy of a measurement.