subject predicate object context
35021 Creator 56412434212aaec1af1a675d5f017f1e
35021 Creator 4419806f183d406a234964f040dbb7da
35021 Creator ext-1bb8933dae13f43a97468da3dfa1683b
35021 Creator ext-6a1a7dcf609cfdfdd46b0897064736c7
35021 Date 2009
35021 Date 2009
35021 Is Part Of p03029743
35021 Is Part Of repository
35021 abstract Intuitively, any `bag of words' approach in IR should benefit from taking term dependencies into account. Unfortunately, for years the results of exploiting such dependencies have been mixed or inconclusive. To improve the situation, this paper shows how the natural language properties of the target documents can be used to transform and enrich the term dependencies to more useful statistics. This is done in three steps. The term co-occurrence statistics of queries and documents are each represented by a Markov chain. The paper proves that such a chain is ergodic, and therefore its asymptotic behavior is unique, stationary, and independent of the initial state. Next, the stationary distribution is taken to model queries and documents, rather than their initial distributions. Finally, ranking is achieved following the customary language modeling paradigm. The main contribution of this paper is to argue why the asymptotic behavior of the document model is a better representation then just the document's initial distribution. A secondary contribution is to investigate the practical application of this representation in case the queries become increasingly verbose. In the experiments (based on Lemur's search engine substrate) the default query model was replaced by the stable distribution of the query. Just modeling the query this way already resulted in significant improvements over a standard language model baseline. The results were on a par or better than more sophisticated algorithms that use fine-tuned parameters or extensive training. Moreover, the more verbose the query, the more effective the approach seems to become.
35021 abstract Intuitively, any `bag of words' approach in IR should benefit from taking term dependencies into account. Unfortunately, for years the results of exploiting such dependencies have been mixed or inconclusive. To improve the situation, this paper shows how the natural language properties of the target documents can be used to transform and enrich the term dependencies to more useful statistics. This is done in three steps. The term co-occurrence statistics of queries and documents are each represented by a Markov chain. The paper proves that such a chain is ergodic, and therefore its asymptotic behavior is unique, stationary, and independent of the initial state. Next, the stationary distribution is taken to model queries and documents, rather than their initial distributions. Finally, ranking is achieved following the customary language modeling paradigm. The main contribution of this paper is to argue why the asymptotic behavior of the document model is a better representation then just the document's initial distribution. A secondary contribution is to investigate the practical application of this representation in case the queries become increasingly verbose. In the experiments (based on Lemur's search engine substrate) the default query model was replaced by the stable distribution of the query. Just modeling the query this way already resulted in significant improvements over a standard language model baseline. The results were on a par or better than more sophisticated algorithms that use fine-tuned parameters or extensive training. Moreover, the more verbose the query, the more effective the approach seems to become.
35021 authorList authors
35021 status peerReviewed
35021 uri http://data.open.ac.uk/oro/document/102374
35021 uri http://data.open.ac.uk/oro/document/98599
35021 uri http://data.open.ac.uk/oro/document/98600
35021 uri http://data.open.ac.uk/oro/document/98601
35021 uri http://data.open.ac.uk/oro/document/98602
35021 uri http://data.open.ac.uk/oro/document/98603
35021 uri http://data.open.ac.uk/oro/document/98604
35021 volume 5766
35021 volume 5766
35021 type AcademicArticle
35021 type Article
35021 label Hoenkamp, Eduard; Bruza, Peter; Song, Dawei and Huang, Qiang (2009). An effective approach to verbose queries using a limited dependencies language model. Lecture Notes in Computer Science, 5766 pp. 116–127.
35021 label Hoenkamp, Eduard; Bruza, Peter; Song, Dawei and Huang, Qiang (2009). An effective approach to verbose queries using a limited dependencies language model. Lecture Notes in Computer Science, 5766 pp. 116–127.
35021 Title An effective approach to verbose queries using a limited dependencies language model
35021 Title An effective approach to verbose queries using a limited dependencies language model
35021 in dataset oro