org.terrier.matching.models

Class DFIC

java.lang.Object

org.terrier.matching.models.WeightingModel

org.terrier.matching.models.DFIC

All Implemented Interfaces:

Serializable, Cloneable, Model

public class DFIC
extends WeightingModel

Divergence From Independence model based on Chi-square statistics (i.e., standardized Chi-squared distance from independence in term frequency tf).

For more information:

A Nonparametric Term Weighting Method for Information Retrieval Based on Measuring the Divergence from Independence. Kocabas, Dincer & Karaoglan, International Journal of Information Retrieval, (to appear), 2013. doi: 10.1007/s10791-013-9225-4.

IRRA at TREC 2012: Index Term Weighting based on Divergence From Independence Model. Dincer, Kocabas & Karaoglan, NIST Special Publication, Proc. of the 20th Text Retrieval Conference, TREC'12, Gaitersburg, MD, USA, 2012.

Since:

3.5

Author:

Bekir Taner Dincer & Craig Macdonald

See Also:

Serialized Form

Field Summary

Fields inherited from class org.terrier.matching.models.WeightingModel

averageDocumentLength, c, cs, documentFrequency, es, i, keyFrequency, numberOfDocuments, numberOfPointers, numberOfTokens, numberOfUniqueTerms, rq, termFrequency

Constructor Summary

Constructors

Constructor and Description
DFIC()

Method Summary

Methods

Modifier and Type	Method and Description
String	getInfo() Returns the name of the model.
double	score(double tf, double docLength) This method provides the contract for implementing weighting models.
double	score(double tf, double docLength, double n_t, double F_t, double keyFrequency) Deprecated.

Methods inherited from class org.terrier.matching.models.WeightingModel

clone, getOverflowed, getParameter, prepare, score, setCollectionStatistics, setEntryStatistics, setKeyFrequency, setParameter, setRequest

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DFIC

public DFIC()

Method Detail

getInfo

public String getInfo()

Description copied from class: WeightingModel

Returns the name of the model.

Specified by:

getInfo in interface Model

Specified by:

getInfo in class WeightingModel

Returns:

java.lang.String

score

public double score(double tf,
           double docLength)

Description copied from class: WeightingModel

This method provides the contract for implementing weighting models.

Specified by:

score in class WeightingModel

Parameters:

tf - The term frequency in the document

docLength - the document's length

Returns:

the score assigned to a document with the given tf and docLength, and other preset parameters

score

@Deprecated
public double score(double tf,
                      double docLength,
                      double n_t,
                      double F_t,
                      double keyFrequency)

Deprecated.

This method provides the contract for implementing weighting models. As of Terrier 3.6, the 5-parameter score method is being deprecated since it is not used. The two parameter score method should be used instead. Tagged for removal in a later version.

Specified by:

score in class WeightingModel

Parameters:

tf - The term frequency in the document

docLength - the document's length

n_t - The document frequency of the term

F_t - the term frequency in the collection

keyFrequency - the term frequency in the query

Returns:

the score returned by the implemented weighting model.