CAREER: Self-adjusting Models as a New Direction in Machine Learning

Indiana University, Bloomington IN

Investigators

Abstract

Machine learning algorithms are now routinely used to build predictive models from data in wide range of applications. However, current approaches to machine learning have an important limitation: They assume that the set of classes observed in a training data set is exhaustive and that new data samples originate from one of the existing classes represented in the training data set. This assumption is unrealistic in many real-world applications in which previously unobserved classes of interest emerge. This study explores a new class of machine learning algorithms that produce self-adjusting models that can accommodate new classes observed in data in offline as well as online learning scenarios. The project aims to (i) use non-parametric models to dynamically incorporate the changing number of classes; (ii) develop new online and offline inference techniques to accommodate new classes as they emerge (iii) automatically associate newly discovered classes with higher-level groups of classes in an attempt to identify potentially interesting class formations, and (iv) develop partially-observed tree models containing observed and unobserved nodes, where observed nodes represent existing classes and unobserved nodes are introduced online to fill the gaps in the existing data hierarchy that become evident only with the arrival of new data. The broader impacts of this work could extend to several real world applications: Bio-security and bio-surveillance, information retrieval, and remote sensing among others in settings where all of the classes are not known a priori. The educational plan includes outreach to K-12 students and enhanced research opportunities for undergraduate and graduate students in computer science as well as at the intersection of computational and life sciences. All the software, publications, and data sets resulting from the project will be freely disseminated to the larger research and educational community. Additional information about the project can be accessed through the project website at http://www.cs.iupui.edu/~dundar/career.html