Directed learning

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Abstract/Contents

Abstract
In machine learning, it is common to treat estimation of model parameters separately from subsequent use of the model to guide decisions. In particular, the learning process typically aims to maximize ``goodness of fit'' without consideration of decision objectives. In this dissertation, we propose a new approach -- directed learning -- which factors decision objectives into the model fitting procedure in order to improve decision quality. We develop and analyze directed learning algorithms for three classes of problems. In the first case, we consider a problem where linear regression analysis is used to guide decision making. We propose directed regression, an efficient algorithm that takes into account the decision objective when computing regression coefficients. We demonstrate through a computational study that directed regression can generate significant performance gains, and establish a theoretical result that motivates it. This setting is then extended to a multi-stage decision problem as our second case, and we show that a variation of directed regression, directed time-series regression, improves performance in this context as well. Lastly, we consider a problem that involves estimating a covariance matrix and making a decision based on that estimate. Such problems arise in portfolio management among other areas, and a common approach is to employ principal component analysis (PCA) to estimate a parsimonious factor model. We propose directed PCA, an efficient algorithm that accounts for the decision objective in the selection of components, and demonstrate through experiments that it leads to significant improvement. We also establish through a theoretical result that the possible degree of improvement can be unbounded.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2012
Issuance monographic
Language English

Creators/Contributors

Associated with Kao, Yi-Hao
Associated with Stanford University, Department of Electrical Engineering
Primary advisor Boyd, Stephen P
Primary advisor Van Roy, Benjamin
Thesis advisor Boyd, Stephen P
Thesis advisor Van Roy, Benjamin
Thesis advisor Hastie, Trevor
Advisor Hastie, Trevor

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Yi-Hao Kao.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2012.
Location electronic resource

Access conditions

Copyright
© 2012 by Yi-Hao Kao
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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