Towards Practical PPM Spam Filtering: Experiments for the TREC 2006 Spam Track.
Andrej Bratko, Bogdan Filipič, Blaž Zupan · 2006
This paper summarizes our participation in the TREC 2006 spam track. We submitted a single filter for the evaluation, based on the Prediction by Partial Matching compression scheme, a method that performed well in the previous TREC evaluation. A major focus of our effort was to improve efficiency of the method, particularly in terms of memory consumption, in order to establish whether compressionbased filters are in fact a viable solution for practical applications. Our system exhibited fair performance, despite the fact that the filtering techniques remained virtually unchanged from the previous evaluation. We did not investigate methods for tackling delayed user feedback. A very simple strategy of training on most recent examples was used for the active learning task, and found to work surprisingly well given its simplicity. 1