Class DFRDependenceScoreModifier

  • All Implemented Interfaces:
    java.lang.Cloneable, DocumentScoreModifier

    public class DFRDependenceScoreModifier
    extends DependenceScoreModifier
    Implements the pBiL and pBil2 DFR-based dependence models. For more information, see Incorporating Term Dependency in the DFR Framework. Jie Peng, Craig Macdonald, Ben He, Vassilis Plachouras, Iadh Ounis. In Proceedings of SIGIR 2007. July 2007. Amsterdam, the Netherlands. 2007.

    Properties

    • See properties for DependenceScoreModifier
    • proximity.norm2 - should Normalisation2 be applied?, defaults to true
    • proximity.norm2.c - c value for Normalisation2, defaults to 1.0
    Author:
    Vassilis Plachouras, Jie Peng, Craig Macdonald
    • Field Detail

      • REC_LOG_2

        protected static final double REC_LOG_2
      • norm2

        protected boolean norm2
        whether to apply Normalisation 2
      • ngramC

        protected double ngramC
    • Constructor Detail

      • DFRDependenceScoreModifier

        public DFRDependenceScoreModifier()
        Constructs an instance of DFRDependenceScoreModifier.
      • DFRDependenceScoreModifier

        public DFRDependenceScoreModifier​(java.lang.String[] pTerms)
        Constructs an instance of DFRDependenceScoreModifier.
        Parameters:
        pTerms -
      • DFRDependenceScoreModifier

        public DFRDependenceScoreModifier​(java.lang.String[] pTerms,
                                          boolean r)
        Constructs an instance of DFRDependenceScoreModifier.
        Parameters:
        pTerms -
        r -
    • Method Detail

      • modifyScores

        public boolean modifyScores​(Index index,
                                    MatchingQueryTerms terms,
                                    ResultSet set)
        Description copied from class: DependenceScoreModifier
        Modifies the scores of documents, in which there exist, or there does not exist a given phrase.
        Specified by:
        modifyScores in interface DocumentScoreModifier
        Overrides:
        modifyScores in class DependenceScoreModifier
        Parameters:
        index - Index the data structures to use.
        terms - MatchingQueryTerms the terms to be matched for the query. This does not correspond to the phrase terms necessarily, but to all the terms of the query.
        set - ResultSet the result set for the query.
        Returns:
        true if any scores have been altered