Abstract: There is provided a method, an apparatus and computer program product for the classification of measured data from a multi-core optical fiber, wherein even with event points which are difficult to distinguish or with identical event points and when there are deviations in distances between event points, connection losses and the like for all event points can be classified. Measured waveform data measured using an OTDR apparatus is read in. Then level differences with connection losses which coincide or exceed a predetermined threshold value are identified as event points, and the event information related to the event points is obtained. Next the event information related to the head core optical fiber is registered in a master file. Then an interval distance between adjacent event points registered in the master file is obtained.