Selective Perception Policies for Guiding Sensing and Computation in Multimodal Systems: A Comparative Analysis

Nuria Oliver and Eric Horvitz

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Intensive computations required for sensing and processing perceptual information can impose significant burdens on personal computer systems. We explore several policies for selective perception in Seer, a multimodal system for recognizing office activity that relies on a layered Hidden Markov Model representation. We review our efforts to employ expected-value-of-information (EVI) computations to limit sensing and analysis in a context-sensitive manner. We discuss an implementation of a one-step myopic EVI analysis and compare the results of using the myopic EVI with a heuristic sensing policy that makes observations at different frequencies. Both policies are then compared to a random perception policy, where sensors are selected at random. Finally, we discuss the sensitivity of ideal perceptual actions to preferences encoded in utility models about information value and the cost of sensing.

Keywords: Selective perception, expected value of information, automatic feature selection, Hidden Markov Models, office awareness, multi-modal interaction, human behavior recognition

In: Proceedings of the Fifth International Conference on Multimodal Interaction, ACM Press, Vancouver, November 2003.

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