Abstract: A relational event history is determined based on a data set, the relational event history. Data is populated in a probability model based on the relational event history, where the probability model is formulated as a series of conditional probabilities that correspond to a set of sequential decisions by an actor for each relational event, where the set of sequential decisions includes at least two decisions as to recipients of a relational event, where the probability model includes one or more statistical parameters and corresponding statistics that relate to one or more of senders, modes, topics, or recipients of relational events. A baseline communications behavior for the relational event history is determined based on the populated probability model, the baseline including a first set of values for the one or more statistical parameters, and departures within the relational event history from the baseline communications behavior are determined.