We define behavior as a set of actions performed by some actor during a period of time. We consider the problem of analyzing a large collection of behaviors by multiple actors, more specifically, identifying typical behaviors and spotting anomalous behaviors. We propose an approach leveraging topic modeling techniques - LDA (Latent Dirichlet Allocation) Ensembles - to represent categories of typical behaviors by topics that are obtained through topic modeling a behavior collection. When such methods are applied to text in natural languages, the quality of the extracted topics are usually judged based on the semantic relatedness of the terms pertinent to the topics. This criterion, however, is not necessarily applicable to topics extracted from non-textual data, such as action sets, since relationships between actions may not be obvious. We have developed a suite of visual and interactive techniques supporting the construction of an appropriate combination of topics based on other criteria, such as distinctiveness and coverage of the behavior set. Two case studies on analyzing operation behaviors in the security management system and visiting behaviors in an amusement park, and the expert evaluation of the first case study demonstrate the effectiveness of our approach.

In the context of the European SCY project, a collaborative, learner-centric TEL environment is described. Reference workflows and workflow executions are analyzed to extract meaningful behavioural attributes automatically. The extracted patterns provide insights into learner behaviour.

If the collection of training data is costly, one can gain by actively selecting particular informative data points in a sequential way. In a Bayesian decision theoretic framework we develop a query selection criterion for classification models which explicitly takes into account the utility of decisions. We determine the overall utility and its derivative with respect to changes of the queries. An optimal query now may be obtained by stochastic hill climbing. Simultaneously, the model structure can be adapted by reversible jump Markov chain Monte Carlo.

If data collection is costly, there is much to be gained by actively se(cid:173) lecting particularly informative data points in a sequential way. In a Bayesian decision-theoretic framework we develop a query selec(cid:173) tion criterion which explicitly takes into account the intended use of the model predictions. By Markov Chain Monte Carlo methods the necessary quantities can be approximated to a desired preci(cid:173) sion. As the number of data points grows, the model complexity is modified by a Bayesian model selection strategy. The proper(cid:173) ties of two versions of the criterion ate demonstrated in numerical experiments.