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  • × author_ss:"Boughanem, M."
  • × theme_ss:"Retrievalalgorithmen"
  1. Hammache, A.; Boughanem, M.: Term position-based language model for information retrieval (2021) 0.00 
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    Abstract
    Term position feature is widely and successfully used in IR and Web search engines, to enhance the retrieval effectiveness. This feature is essentially used for two purposes: to capture query terms proximity or to boost the weight of terms appearing in some parts of a document. In this paper, we are interested in this second category. We propose two novel query-independent techniques based on absolute term positions in a document, whose goal is to boost the weight of terms appearing in the beginning of a document. The first one considers only the earliest occurrence of a term in a document. The second one takes into account all term positions in a document. We formalize each of these two techniques as a document model based on term position, and then we incorporate it into a basic language model (LM). Two smoothing techniques, Dirichlet and Jelinek-Mercer, are considered in the basic LM. Experiments conducted on three TREC test collections show that our model, especially the version based on all term positions, achieves significant improvements over the baseline LMs, and it also often performs better than two state-of-the-art baseline models, the chronological term rank model and the Markov random field model.
    Type
    a
  2. Boughanem, M.; Chrisment, C.; Tamine, L.: On using genetic algorithms for multimodal relevance optimization in information retrieval (2002) 0.00 
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    Abstract
    Boughanem, Chrisment, and Tamine use 144,186 documents and 25 queries from the TREC corpus AP88 to evaluate a genetic algorithm for multiple query evaluation against single query evaluation. They demonstrate niche construction by the use of a genetic technique to reproduce queries more often if they retrieve more relevant documents (genotypic sharing), or if they have close evaluation results (phenotypic sharing).New documents generated in each iteration are ranked by a merge based on one of these two principles. Genotypic sharing yields improvements of from 6% to 15% over single query evaluation, and phenotypic sharing shows from 5% to 15% improvement. Thus the niching technique appears to offer the possibility of successful merging of different query expressions.
    Type
    a

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