A determination device includes: a memory; and a processor coupled to the memory and configured to: obtain sensor data on motion of a device from a plurality of sensors, extract, from the sensor data, data related to an anomaly based on a threshold value used in detecting the anomaly with use of the sensor data, convert the data related to the anomaly into structural data having a graph structure focusing on an analogous relationship between or among the plurality of sensors, and generate a classifier that identifies a cause of the anomaly with use of the structural data.