Comparing Non-projective Strategies for Labeled Graph-Based Dependency Parsing
نویسندگان
چکیده
We fill a gap in the systematically analyzed space of available techniques for state-of-the-art dependency parsing by comparing non-projective strategies for graph-based parsers. Using three languages with varying frequency of non-projective constructions, we compare the non-projective approximation algorithm with pseudo-projective parsing. We also analyze the differences between different encoding schemes for pseudo-projective parsing. We find only minor differences between the encoding schemes for pseudo-projective parsing, and that the non-projective approximation algorithm is superior to pseudo-projective parsing.
منابع مشابه
Maximum Spanning Tree Algorithm for Non-projective Labeled Dependency Parsing
Following (McDonald et al., 2005), we present an application of a maximum spanning tree algorithm for a directed graph to non-projective labeled dependency parsing. Using a variant of the voted perceptron (Collins, 2002; Collins and Roark, 2004; Crammer and Singer, 2003), we discriminatively trained our parser in an on-line fashion. After just one epoch of training, we were generally able to at...
متن کاملPseudo-Projective Dependency Parsing
In order to realize the full potential of dependency-based syntactic parsing, it is desirable to allow non-projective dependency structures. We show how a datadriven deterministic dependency parser, in itself restricted to projective structures, can be combined with graph transformation techniques to produce non-projective structures. Experiments using data from the Prague Dependency Treebank s...
متن کاملExtracting Narrative Timelines as Temporal Dependency Structures
We propose a new approach to characterizing the timeline of a text: temporal dependency structures, where all the events of a narrative are linked via partial ordering relations like BEFORE, AFTER, OVERLAP and IDENTITY. We annotate a corpus of children’s stories with temporal dependency trees, achieving agreement (Krippendorff’s Alpha) of 0.856 on the event words, 0.822 on the links between eve...
متن کاملAn improved joint model: POS tagging and dependency parsing
Dependency parsing is a way of syntactic parsing and a natural language that automatically analyzes the dependency structure of sentences, and the input for each sentence creates a dependency graph. Part-Of-Speech (POS) tagging is a prerequisite for dependency parsing. Generally, dependency parsers do the POS tagging task along with dependency parsing in a pipeline mode. Unfortunately, in pipel...
متن کاملA Transition-Based System for Joint Part-of-Speech Tagging and Labeled Non-Projective Dependency Parsing
Most current dependency parsers presuppose that input words have been morphologically disambiguated using a part-of-speech tagger before parsing begins. We present a transitionbased system for joint part-of-speech tagging and labeled dependency parsing with nonprojective trees. Experimental evaluation on Chinese, Czech, English and German shows consistent improvements in both tagging and parsin...
متن کامل