Abstract

Abstract
We present a case study in which sequence mining algorithms were applied to web access log data. The data are from a portal that is targeted for business users. In this portal, like in many others, content is described using a set of descriptors, such as keywords, category and type. We investigate whether representing content by the type rather than its identifier enables existing sequence mining methods to obtain interesting patterns. Rather than a more traditional approach based on measures such as support and confidence, we analyze results from an application perspective. This enables us to identify opportunities for improving and extending these methods.

Abstract

Abstract

Abstract
The problem of learning rankings is receiving increased attention from several research communities. In this paper we empirically evaluate an adaptation of the algorithm of learning decision trees for rankings. Our experiments are carried out on some metalearning problems, which consist of relating characteristics of learning problems to the relative performance of learning algorithms. We obtain positive results which, somewhat surprisingly, indicate that the method predicts more accurately the top ranks. Copyright © 2008, Association for the Advancement of Artificial Intelligence.

Abstract
Due to the wide variety of algorithms for supervised classification originating from several research areas, selecting one of them to apply on a given problem is not a trivial task. Recently several methods have been developed to create rankings of classification algorithms based on their previous performance. Therefore, it is necessary to develop techniques to evaluate and compare those methods. We present three measures to evaluate rankings of classification algorithms, give examples of their use and discuss their characteristics.