The method is used to characterize a yarn moved along the longitudinal direction thereof. Measured values of a property of the yarn along the longitudinal direction of the yarn are captured. The measured values are used to determine values of a yarn parameter. An event field (3) is provided, which contains a quadrant of a two-dimensional Cartesian coordinate system, the abscissa (31) of which indicates an extension of yarn parameter values in the longitudinal direction and the ordinate (32) of which indicates a deviation of the yarn parameter from a target value. The values of the yarn parameter and the extension thereof in the longitudinal direction are used to determine the densities of events in the event field (3). A yarn body is depicted as a surface (4) in the event field (3). The surface (4) is delimited both by the abscissa (31) and by the ordinate (32), and furthermore by a line (41) in the event field (3), which substantially follows a constant event density. The depiction of the yarn body allows the quick and efficient specification of a cleaning boundary (6).