Are crossing dependencies really scarce?

The syntactic structure of a sentence can be modelled as a tree, where vertices correspond to words and edges indicate syntactic dependencies. It has been claimed recurrently that the number of edge crossings in real sentences is small. However, a baseline or null hypothesis has been lacking. Here w...

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Detalles Bibliográficos
Autores: Ferrer Cancho, Ramon|||0000-0002-7820-923X, Gómez Rodríguez, Carlos, Esteban Ángeles, Juan Luis|||0000-0003-0072-6576
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/112359
Acceso en línea:https://hdl.handle.net/2117/112359
https://dx.doi.org/10.1016/j.physa.2017.10.048
Access Level:acceso abierto
Palabra clave:Computational linguistics
Baselines
Crossings
Spatial networks
Syntactic dependency trees
Lingüística computacional
Àrees temàtiques de la UPC::Informàtica::Intel·ligència artificial::Llenguatge natural
Descripción
Sumario:The syntactic structure of a sentence can be modelled as a tree, where vertices correspond to words and edges indicate syntactic dependencies. It has been claimed recurrently that the number of edge crossings in real sentences is small. However, a baseline or null hypothesis has been lacking. Here we quantify the amount of crossings of real sentences and compare it to the predictions of a series of baselines. We conclude that crossings are really scarce in real sentences. Their scarcity is unexpected by the hubiness of the trees. Indeed, real sentences are close to linear trees, where the potential number of crossings is maximized.