Abstract: A disclosed example includes obtaining first data associated with a first device class; build a vocabulary including keys that map to values for an incremental training batch, the incremental training batch based on the first data and exemplars from memory, the exemplars associated with a set of device classes, the exemplars include first means closest to first overall means for ones of the set of the device classes that were stored to the at least one memory during a previous incremental training batch; train a model based on the keys as input features and an updated set of the device classes that includes the first device class; and select a set of samples from the first data and the exemplars, the set of the samples includes second means closest to second overall means for ones of the updated set of the device classes.