Class DPH

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

    public class DPH
    extends WeightingModel
    This class implements the DPH hypergeometric weighting model. P stands for Popper's normalization. This is a parameter-free weighting model. Even if the user specifies a parameter value, it will NOT affect the results. It is highly recomended to use the model with query expansion.


    1. FUB, IASI-CNR and University of Tor Vergata at TREC 2007 Blog Track. G. Amati and E. Ambrosi and M. Bianchi and C. Gaibisso and G. Gambosi. Proceedings of the 16th Text REtrieval Conference (TREC-2007), 2008.
    2. Frequentist and Bayesian approach to Information Retrieval. G. Amati. In Proceedings of the 28th European Conference on IR Research (ECIR 2006). LNCS vol 3936, pages 13--24.
    Gianni Amati, Ben He, Vassilis Plachouras
    See Also:
    Serialized Form
    • Constructor Detail

      • DPH

        public DPH()
        A default constructor.
    • Method Detail

      • getInfo

        public final java.lang.String getInfo()
        Returns the name of the model.
        Specified by:
        getInfo in interface Model
        Specified by:
        getInfo in class WeightingModel
        the name of the model
      • score

        public final double score​(double tf,
                                  double docLength)
        Uses DPH to compute a weight for a term in a document.
        Specified by:
        score in class WeightingModel
        tf - The term frequency in the document
        docLength - the document's length
        the score assigned to a document with the given tf and docLength, and other preset parameters