Efficient Classification of Multi-Labelled Text Streams by Clashing

TL;DR

This paper introduces a novel online method called Clashing for classifying multi-labelled text streams efficiently, using constant memory and processing time, and demonstrates its competitive performance on real-world data.

Contribution

The paper presents a new online classification approach that maps text into a low-dimensional space and partitions it for multi-label prediction, suitable for infinite data streams.

Findings

Achieves competitive F measures with less computational resources.

Outperforms similar methods in macro-averaged F measure.

Learns faster from partially labelled streams.

Abstract

We present a method for the classification of multi-labelled text documents explicitly designed for data stream applications that require to process a virtually infinite sequence of data using constant memory and constant processing time. Our method is composed of an online procedure used to efficiently map text into a low-dimensional feature space and a partition of this space into a set of regions for which the system extracts and keeps statistics used to predict multi-label text annotations. Documents are fed into the system as a sequence of words, mapped to a region of the partition, and annotated using the statistics computed from the labelled instances colliding in the same region. This approach is referred to as clashing. We illustrate the method in real-world text data, comparing the results with those obtained using other text classifiers. In addition, we provide an analysis about the effect of the representation space dimensionality on the predictive performance of the system. Our results show that the online embedding indeed approximates the geometry of the full corpus-wise TF and TF-IDF space. The model obtains competitive F measures with respect to the most accurate methods, using significantly fewer computational resources. In addition, the method achieves a higher macro-averaged F measure than methods with similar running time. Furthermore, the system is able to learn faster than the other methods from partially labelled streams.