Features

Index

• LX-DepParser
• Parser
• Tagset
• Annotation guidelines
• Authorship
• Contacts
• Acknowledgments

LX Dependency Parser

LX-DepParser (beta) is a free online service for the syntactic analysis of Portuguese. It allows the automatic parsing of sentences in Portuguese in terms of their grammatical functions.

This service was developed and is maintained at the University of Lisbon by the NLX-Speech and Natural Language Group, Department of Informatics.

Parser

LX-DepParser is a MSTParser trained with Portuguese data.

For the training of the parser, 22,118 sentences were used (comprising 250,056 word tokens). The sentences were taken from the CINTIL-Treebank. This treebank is being developed and maintained at the University of Lisbon by the NLX-Speech and Natural Language Group of the Department of Informatics. In terms of evaluation, LX-DepParser's UAS (unlabeled attachment score) is 94.42 and its LAS (labeled attachment score) is 91.23. Scores were obtained through 10-fold cross-validation.

Tagset

Part-of-speech tags (high granularity)

Tag	Meaning
A	Adjective
AP	Adjective Phrase
ADV	Adverb
ADVP	Adverb Phrase
C	Complementizer
CP	Complementizer Phrase
CARD	Cardinal
CONJ	Conjuction
CONJP	Conjuction Phrase
D	Determiner
DEM	Demonstrative
N	Noun
NP	Noun Phrase
P	Preposition
PP	Preposition Phrase
POSS	Possessive
QNT	Predeterminer
S	Sentence
V	Verb
VP	Verb Phrase

Part-of-speech tags (low granularity)

Inflection tags

Gramatical Function Tagset

Tag	Meaning
C	Complement
CARD	Cardinal in multi-word cardinals
COORD	Coordination
CONJ	Conjunction
DO	Direct Object
IO	Indirect Object
OBL	Oblique Object
M	Modifier
N	Relationship between words and named entities
OBL	Oblique Complement
PUNCT	Punctuation
PRD	Predicate
SJ	Subject
SJac	Subject of an anticausative
SJcp	Subject of complex predicate
SP	Specifier

Annotation guidelines

The analyses produced by LX-DepParser are similar to the dependency representations found in the dependency treebank on which LX-DepParser was trained. This dependency treebank was designed along the principles described in the following handbook:

Branco António, Sérgio Castro, João Silva, Francisco Costa, 2011, CINTIL DepBank Handbook: Design options for the representation of grammatical dependencies. Department of Informatics, University of Lisbon, Technical Reports series, nb. di-fcul-tr-11-03.

Authorship

LX-DepParser is being developed by Rúben Reis, under the direction of António Branco in NLX-Group on Natural Language and Speech.

Contacts

You can contact us at the following email address: 'nlx' followed by '@' followed by 'di.fc.ul.pt'.

Acknowledgments

LX-DepParser was partially funded by FCT-Foundation for Science and Technology, under the contract FCT/PTDC/PLP/81157/2006 for the project SemanticShare.