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Tech Report kmi-97-21 Abstract


Bayesian Inference with Missing Data Using Bound and Collapse
Techreport ID: kmi-97-21
Date: 1997
Author(s): Paola Sebastiani and Marco Ramoni
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Current Bayesian methods to estimate conditional probabilities from samples with missing data pose serious problems of robustness and computational efficiency. This paper introduces a new method, called Bound and Collapse (BC), able to overcome these problems. When no information is available on the pattern of missing data, BC turns {em bounds} on the possible estimates consistent with the available information. These bounds can be then collapsed to a point estimate using information about the pattern of missing data, if any. Approximations of the variance and of the posterior distribution are proposed, and their accuracy is compared to approximations based on alternative methods in a real data set of polling data subject to non-response. 1. Department of Actuarial Science and Statistics, City University. 2. Knowledge Media Institute, The Open University.
 
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Creating learning organisations hinges on managing knowledge at many levels. Knowledge can be provided by individuals or it can be created as a collective effort of a group working together towards a common goal, it can be situated as "war stories" or it can be generalised as guidelines, it can be described informally as comments in a natural language, pictures and technical drawings or it can be formalised as mathematical formulae and rules, it can be expressed explicitly or it can be tacit, embedded in the work product. The recipient of knowledge - the learner - can be an individual or a work group, professionals, university students, schoolchildren or informal communities of interest.
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