Cost-Sensitive Tree of Classifiers
This addresses the need for efficient, cost-sensitive machine learning in large-scale industrial applications like search engines and spam filters, representing an incremental improvement over existing methods.
The paper tackles the problem of balancing test-time computational cost and classifier accuracy by constructing a tree of classifiers that optimizes feature extraction for specific input sub-partitions, achieving state-of-the-art accuracy at a small fraction of the computational cost.
Recently, machine learning algorithms have successfully entered large-scale real-world industrial applications (e.g. search engines and email spam filters). Here, the CPU cost during test time must be budgeted and accounted for. In this paper, we address the challenge of balancing the test-time cost and the classifier accuracy in a principled fashion. The test-time cost of a classifier is often dominated by the computation required for feature extraction-which can vary drastically across eatures. We decrease this extraction time by constructing a tree of classifiers, through which test inputs traverse along individual paths. Each path extracts different features and is optimized for a specific sub-partition of the input space. By only computing features for inputs that benefit from them the most, our cost sensitive tree of classifiers can match the high accuracies of the current state-of-the-art at a small fraction of the computational cost.