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Activity Number:
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248
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Type:
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Contributed
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Date/Time:
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Tuesday, July 31, 2007 : 8:30 AM to 10:20 AM
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Sponsor:
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IMS
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| Abstract - #309762 |
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Title:
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Effects of Rounding of Conditional Frequencies on Odds Ratio
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Author(s):
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Juyoun Lee*+ and Aleksandra Slavkovic
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Companies:
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The Pennsylvania State University and The Pennsylvania State University
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Address:
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3310 Plaza Drive, State College, PA, 16801,
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Keywords:
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Rounding ; Log-Odds ratio ; Odds ratio ; Contingency Table ; Conditional Frequencies
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Abstract:
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The conditional frequencies (i.e., rates) for tabular data are usually expressed as reals approximated to the true values by rounding at different decimal places. This rounding issue provides the following questions: (1) Can we say that the rounded data are still same as the unrounded data? (2) What are the effects of rounding on parameters, such as odds-ratios? These questions are highly relevant for data privacy and statistical disclosure limitation. By using tools from algebraic statistics, we investigate the difference between distributions of rounded and unrounded data. We specify the effects of the rounding on odds-ratio, and compare the bounds of cell counts and the space of the possible tables which have same conditional frequencies. We demonstrate these results with a simple example.
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