1. A method of deriving output data from information relating to the transmission of messages by an entity over time, using a predictive model, comprising the steps of: (i) creating a first signature comprising a plurality of parameters related to the transmission of the messages over a predetermined first time period, and creating a second signature comprising a plurality of parameters related to the transmission of messages over a second period shorter than the first and more recent than the first; wherein the signatures are created in one of a plurality of predetermined possible formats; (ii) updating the first signature by a weighted averaging with the second signature, (iii) dynamically configuring said model at least according to the format of the signatures; and (iv) deriving the output data from the information by inputting the signatures to the model.