The invention relates to a method for detecting geometric deviations of a real movement guidance process from an ideal movement guidance process in a coordinate measuring device, which has a sensor for measuring a workpiece, or in a machine tool, which has a tool for machining a workpiece. The coordinate measuring device or the machine tool has a movable part which is guided along a movement guide and by the movement guide. The movable part is moved in a forward direction along the movement guide, and a respective measurement value of the geometric deviation is detected at a plurality of first positions (21) of the movable part with respect to the movement guide such that a first group of measurement values is detected; and the movable part is moved along the movement guide in a reverse direction which runs opposite the forward direction, and a respective measurement value of the geometric deviation is detected at a plurality of second positions (11) of the movable part with respect to the movement guide such that a second group of measurement values is detected. When detecting the first group of measurement values, no measurement values are detected at at least one first intermediate position (22) which lies between two of the first positions (21) and one of the second positions (11), and/or when detecting the second group of measurement values, no measurement values are detected at at least one second intermediate position (12) which lies between two of the second positions (11) and one of the first positions (21). For each of the first positions (21) and for each of the second positions (11), an average value (31) of the geometric movement guidance deviation is calculated from the curve (20) of the first group of measurement values along the movement guide and from the curve (10) of the second group of measurement values along the movement guide, and in this manner, a group of average values is formed which are the average values of the geometric deviations during the movement of the movable part in the forward direction and in the reverse direction.