Is the unigram relevance model term independent?
Mike Symonds, Peter Bruza, Guido Zuccon, Laurianne Sitbon, Ian Turner · 2012
This paper develops a framework for classifying term dependencies in query expansion with respect to the role terms play in structural linguistic associations. The framework is used to classify and compare the query expansion terms produced by the unigram and positional relevance models. As the unigram relevance model does not explicitly model term dependencies in its estimation process it is often thought to ignore dependencies that exist between words in natural language.