A method for ascertaining a position error in a linear drive, a linear drive, a method for operating the linear drive and an installation, wherein the deviation of a respective further runner in relation to a first runner (reference runner) is ascertained to determine the position error, where the discrepancy of the respective sensor is ascertained based on the deviation of the runner, the discrepancy may be ascertained using a reference system, the position error may be established based on the discrepancy of the respective sensor PS and the deviation of the respective runner, and where the position error may serve for the improved positioning, i.e., more precise positioning, of the respective runner on the linear drive or of the segments.