org.dkpro.statistics.agreement.distance

Class IntervalDistanceFunction

java.lang.Object

org.dkpro.statistics.agreement.distance.IntervalDistanceFunction

All Implemented Interfaces:

IDistanceFunction

Direct Known Subclasses:

SquareDistanceFunction

public class IntervalDistanceFunction
extends Object
implements IDistanceFunction

Implementation of the IDistanceFunction interface for scoring the distance between interval-scaled categories. That is to say, categories represent a numerical value whose difference can be measured. A typical example is date as measures, for instance, using the Gregorian calendar. We are able to measure the difference between the years 2010 and 2000 and to say that the difference equals the difference between he years 1980 and 1970. However, we cannot say that 2000 is twice the year 1000, since there is no absolute zero (note that the year 0 is arbitrarily defined and that we need to cater for years such as 200 BCE). For natural language processing tasks, judging the similarity between two entities on a linear scale of, say, 1 to 6 is another example for interval-scaled data. Mathematically, the interval scale only allows for the equality, comparison, and addition operations, but prohibits multiplication. The distance function returns the squared difference between the numerical representation of two categories. It thus assumes the categories to be integers or doubles and falls back to a NominalDistanceFunction for other data types.

References:

• Krippendorff, K.: Content Analysis: An Introduction to Its Methodology. Beverly Hills, CA: Sage Publications, 1980.

Author:

Christian M. Meyer

See Also:

IDistanceFunction

Constructor Summary

Constructors

Constructor and Description
IntervalDistanceFunction()

Method Summary

Modifier and Type	Method and Description
double	measureDistance(IAnnotationStudy study, Object category1, Object category2) Returns a distance value for the given pair of categories used within the given annotation study.

Methods inherited from class java.lang.Object

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

Constructor Detail

IntervalDistanceFunction

public IntervalDistanceFunction()

Method Detail

measureDistance

public double measureDistance(IAnnotationStudy study,
                              Object category1,
                              Object category2)

Description copied from interface: IDistanceFunction

Returns a distance value for the given pair of categories used within the given annotation study. Normally, the measure should return a distance of 0 if, and only if, the two categories are equal and a positive number otherwise.

Specified by:

measureDistance in interface IDistanceFunction