Parse thicket
A parse thicket is a graph that represents the syntactic structure of a paragraph of text in natural language processing. A parse thicket includes parse tree for each sentence for this paragraph plus some arcs for other relations between words other than syntactic.[1] Parse thickets can be constructed for both constituency parse trees and dependency parse trees. The relations which link parse trees within a parse thicket are:[2]
- Coreferences;
- The same entity / sub-entity / super-entity;
- Rhetorical Structure and other discourse relation;
- Speech act-based relations.
To assess similarity between texts, such as a question and its candidate answers, parse thickets can be generalized [3]
In the image of parse thicket coreferences and entity-entity links are shown in solid red, and rhetoric/speech act relations are shown in dotted red. ETAP parser and tree visualization software is used.[4]
To compute generalization of two parse thickets, one needs to find their maximum common sub-graph (sub-thicket).[5]
References
- Galitsky B, Kuznetsov SO, Usikov DA. Parse Thicket Representation for Multi-sentence Search. Lecture Notes in Computer Science. 2013;7735:1072-1091. doi:10.1007/978-3-642-35786-2_12.
- Galitsky B, Ilvovsky D, Kuznetsov SO, Strok F. Matching sets of parse trees for answering multi-sentence questions. Recent Advances in Natural Language Processing. 2013.
- Galitsky B. Machine learning of syntactic parse trees for search and classification of text. Engineering Applications of Artificial Intelligence. 2013;26(3):153-172. doi:10.1016/j.engappai.2012.09.017.
- Boguslavsky, I., Iomdin, L., Sizov V.. Interactive enconversion by means of the ETAP-3 system. Culture, Language and Information Technologies. 2003.
- Galitsky B, Ilvovsky D, Kuznetsov SO, Strok F. Finding Maximal Common Sub-parse Thickets for Multi-sentence Search. Lecture Notes in Artificial Intelligence. 2013;8323.
External links
- [Google code page https://code.google.com/p/relevance-based-on-parse-trees/]
- [Stanford NLP http://nlp.stanford.edu/]
- [OpenNLP Similarity component https://issues.apache.org/jira/browse/OPENNLP/component/12316412]