Duplicate News Story Detection Revisited

In this paper, we investigate near-duplicate detection, particularly looking at the detection of evolving news stories. These stories often consist primarily of syndicated information, with local replacement of headlines, captions, and the addition of locally-relevant content. By detecting near-duplicates, we can offer users only those stories with content materially different from previously-viewed versions of the story. We expand on previous work and improve the performance of near-duplicate document detection by weighting the phrases in a sliding window based on the term frequency within the document of terms in that window and inverse document frequency of those phrases. We experiment on a subset of a publicly available web collection that is comprised solely of documents from news web sites. News articles are particularly challenging due to the prevalence of syndicated articles, where very similar articles are run with different headlines and surrounded by different HTML markup and site templates. We evaluate these algorithmic weightings using human judgments to determine similarity. We find that our techniques outperform the state of the art with statistical significance and are more discriminating when faced with a diverse collection of documents.