Stanford Core NLP - understanding coreference resolution

Question

I'm having some trouble understanding the changes made to the coref resolver in the last version of the Stanford NLP tools. As an example, below is a sentence and the corresponding CorefChainAnnotation: The atom is a basic unit of matter, it consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. {1=[1 1, 1 2], 5=[1 3], 7=[1 4], 9=[1 5]} I am not sure I understand the meaning of these numbers. Looking at the source doesn't really help either. Thank you JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

I've been working with the coreference dependency graph and I started by using the other answer to this question. After a while though I realized that this algorithm above is not exactly correct. The output it produced is not even close to the modified version I have. For anyone else who uses this article, here is the algorithm I ended up with which also filters out self references because every representativeMention also mentions itself and a lot of mentions only reference themselves. Map coref = document.get(CorefChainAnnotation.class); for(Map.Entry entry : coref.entrySet()) { CorefChain c = entry.getValue(); //this is because it prints out a lot of self references which aren't that useful if(c.getCorefMentions().size() <= 1) continue; CorefMention cm = c.getRepresentativeMention(); String clust = ""; List<CoreLabel> tks = document.get(SentencesAnnotation.class).get(cm.sentNum-1).get(TokensAnnotation.class); for(int i = cm.startIndex-1; i < cm.endIndex-1; i++) clust += tks.get(i).get(TextAnnotation.class) + " "; clust = clust.trim(); System.out.println("representative mention: \"" + clust + "\" is mentioned by:"); for(CorefMention m : c.getCorefMentions()){ String clust2 = ""; tks = document.get(SentencesAnnotation.class).get(m.sentNum-1).get(TokensAnnotation.class); for(int i = m.startIndex-1; i < m.endIndex-1; i++) clust2 += tks.get(i).get(TextAnnotation.class) + " "; clust2 = clust2.trim(); //don't need the self mention if(clust.equals(clust2)) continue; System.out.println("\t" + clust2); } } And the final output for your example sentence is the following: representative mention: "a basic unit of matter" is mentioned by: The atom it Usually "the atom" ends up being the representative mention but in the case it doesn't surprisingly. Another example with a slightly more accurate output is for the following sentence: The Revolutionary War occurred during the 1700s and it was the first war in the United States. produces the following output: representative mention: "The Revolutionary War" is mentioned by: it the first war in the United States