Small sample feature selection

dc.contributorDougherty, Edward R.
dc.creatorSima, Chao
dc.date.accessioned2007-09-17T19:33:11Z
dc.date.accessioned2017-04-07T19:53:19Z
dc.date.available2007-09-17T19:33:11Z
dc.date.available2017-04-07T19:53:19Z
dc.date.created2003-05
dc.date.issued2007-09-17
dc.description.abstractHigh-throughput technologies for rapid measurement of vast numbers of biolog- ical variables offer the potential for highly discriminatory diagnosis and prognosis; however, high dimensionality together with small samples creates the need for fea- ture selection, while at the same time making feature-selection algorithms less reliable. Feature selection is required to avoid overfitting, and the combinatorial nature of the problem demands a suboptimal feature-selection algorithm. In this dissertation, we have found that feature selection is problematic in small- sample settings via three different approaches. First we examined the feature-ranking performance of several kinds of error estimators for different classification rules, by considering all feature subsets and using 2 measures of performance. The results show that their ranking is strongly affected by inaccurate error estimation. Secondly, since enumerating all feature subsets is computationally impossible in practice, a suboptimal feature-selection algorithm is often employed to find from a large set of potential features a small subset with which to classify the samples. If error estimation is required for a feature-selection algorithm, then the impact of error estimation can be greater than the choice of algorithm. Lastly, we took a regression approach by comparing the classification errors for the optimal feature sets and the errors for the feature sets found by feature-selection algorithms. Our study shows that it is unlikely that feature selection will yield a feature set whose error is close to that of the optimal feature set, and the inability to find a good feature set should not lead to the conclusion that good feature sets do not exist.
dc.identifier.urihttp://hdl.handle.net/1969.1/5796
dc.language.isoen_US
dc.publisherTexas A&M University
dc.subjectfeature selection
dc.subjectclassification
dc.subjectmicroarray
dc.subjectsmall sample
dc.titleSmall sample feature selection
dc.typeBook
dc.typeThesis

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