Systematic

Means that the error in a measured value is determined by dependence on some factors; systematic error could in principle be corrected for if the dependencies were understood and the factors were known; where the factors vary negligibly across many measurements, the errors from the systematic effect are the same; “systematic” implies “predictable” (in principle, not in practice) and “correlated across measurements”; systematic errors therefore “average out” slowly or not at all across many measured values; systematic effects may be operating at the same time as other types of effect, in which case only a component of the total error is systematic; an example of a systematic effect is a mis-characterised calibration target.