001/** 002 * Copyright (c) 2011, The University of Southampton and the individual contributors. 003 * All rights reserved. 004 * 005 * Redistribution and use in source and binary forms, with or without modification, 006 * are permitted provided that the following conditions are met: 007 * 008 * * Redistributions of source code must retain the above copyright notice, 009 * this list of conditions and the following disclaimer. 010 * 011 * * Redistributions in binary form must reproduce the above copyright notice, 012 * this list of conditions and the following disclaimer in the documentation 013 * and/or other materials provided with the distribution. 014 * 015 * * Neither the name of the University of Southampton nor the names of its 016 * contributors may be used to endorse or promote products derived from this 017 * software without specific prior written permission. 018 * 019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR 023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 029 */ 030/** 031 * 032 */ 033package org.openimaj.experiment.evaluation.agreement; 034 035import java.util.Map; 036 037/** 038 * Calculates the percentage interrater agreement for a given dataset between 039 * two (and only two) raters. 040 * 041 * @author David Dupplaw (dpd@ecs.soton.ac.uk) 042 * @created 12 Aug 2013 043 */ 044public class PercentageInterraterAgreement 045{ 046 /** 047 * The input should be a {@link Map} for each rater where the keys represent 048 * all the subjects that were rated by the raters and the values represent 049 * the annotations given by the raters. Agreement between the raters is 050 * determined by {@link #equals(Object)} for the INSTANCE type. Annotations 051 * for subjects which are not in both sets are ignored. 052 * 053 * @param rater1 054 * The annotations from rater 1 055 * @param rater2 056 * The annotations from rater 2 057 * @return The percentage agreement 058 */ 059 public static <K, A> double calculate( 060 final Map<K, A> rater1, 061 final Map<K, A> rater2) 062 { 063 int totalCount = 0; 064 int agreementCount = 0; 065 066 for (final K subjectKey : rater1.keySet()) 067 { 068 // We can only form an agreement if both raters rated this 069 // specific subject, so let's check 070 if (rater2.keySet().contains(subjectKey)) 071 { 072 final A r1a = rater1.get(subjectKey); 073 final A r2a = rater2.get(subjectKey); 074 075 // It's possible that the key exists but is mapped to 076 // a null value (for example, if majority voting was used 077 // to generate the set and there was no majority). 078 if (r1a == null || r2a == null) 079 continue; 080 081 // Get the answers from the raters 082 final A annotation1 = r1a; 083 final A annotation2 = r2a; 084 085 // Count the agreements 086 if (annotation1.equals(annotation2)) 087 agreementCount++; 088 089 // Keep a running total 090 totalCount++; 091 } 092 } 093 094 final double PrA = agreementCount / (double) totalCount; 095 return PrA; 096 } 097}