This dissertation studies how the mechanism-based view of causality can assist in construction and utilization of causal models for decision support. The mechanism-based view of causality is based on the theory of causal ordering, proposed by Simon [53], which explicates causal asymmetries among variables in a self-contained set of simultaneous structural equations. I extend the theory of causal ordering to explicate causal relations in under-constrained sets of structural equations. Considering under constrained models as intermediate representations of one's understanding of decision problems, I demonstrate that a model construction process can be viewed as the process of assembling mechanisms from under-constrained models into self-contained causal models. I formalize the reversibility property of a mechanism to support changes in structure in causal models containing reversible mechanisms. I introduce algorithms for deliberating atomic actions when one considers manipulating a variable or releasing a mechanism to achieve a decision objective. In addition, I introduce the concept of search for opportunities which amounts to both identifying the set of policy variables and computing their optimal setting for a decision objective. Search for opportunities presents decision makers with a list of ranked interventions based on the value of intervention computation. I implement an interactive system called ImaGeNIe that supports mechanism-based model construction and utilization. I conduct subject experiments and find that ImaGeNIe can effectively assist users in constructing causal models for causal reasoning.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-12082003-172253 |
| Date | 16 January 2004 |
| Creators | Lu, Tsai-Ching |
| Contributors | Gregory F. Cooper, Krzysztof W. Przytula, Marek J. Druzdzel, Milos Hauskrecht |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/zip |
| Source | http://etd.library.pitt.edu/ETD/available/etd-12082003-172253/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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