Translation Error-  The deviation (error) of a point's position from an expected, nominal, or commanded position or displacement. There must be a defined or physical reference point, line, plane or coordinate system from which the deviation is determined. See also straightness error, reference coordinate system.

If the translation error of a body is to be determined, there must be a specified point on that body that defines the measurement because of concurrent rotational (angular) motions of the body.