GALE Arabic-English Parallel Aligned Treebank -- Newswire

Item Name: GALE Arabic-English Parallel Aligned Treebank -- Newswire
Authors: Xuansong Li, Stephen Grimes, Safa Ismael, Dalal Zakhary, Stephanie Strassel, Mohamed Maamouri, Ann Bies
LDC Catalog No.: LDC2013T10
ISBN: 1-58563-644-4
Release Date: May 15, 2013
Data Type: text
Data Source(s): newswire
Project(s): GALE
Application(s): automatic content extraction, cross-lingual information retrieval, information detection, machine translation
Language(s): Arabic, English
Language ID(s): arb, eng
Distribution: Web Download
Member fee: $0 for 2013 members
Non-member Fee: US $1750.00
Reduced-License Fee: N/A
Extra-Copy Fee: US $
Non-member License: yes
Online documentation: yes
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Xuansong Li, et al.
GALE Arabic-English Parallel Aligned Treebank -- Newswire
Linguistic Data Consortium, Philadelphia


GALE Arabic-English Parallel Aligned Treebank -- Newswire was developed by the Linguistic Data Consortium (LDC) and contains 267,520 tokens of word aligned Arabic and English parallel text with treebank annotations. This material was used as training data in the DARPA GALE (Global Autonomous Language Exploitation) program.

Parallel aligned treebanks are treebanks annotated with morphological and syntactic structures aligned at the sentence level and the sub-sentence level. Such data sets are useful for natural language processing and related fields, including automatic word alignment system training and evaluation, transfer-rule extraction, word sense disambiguation, translation lexicon extraction and cultural heritage and cross-linguistic studies. With respect to machine translation system development, parallel aligned treebanks may improve system performance with enhanced syntactic parsers, better rules and knowledge about language pairs and reduced word error rate.

In this release, the source Arabic data was translated into English. Arabic and English treebank annotations were performed independently. The parallel texts were then word aligned. The material in this corpus corresponds to the Arabic treebanked data appearing in Arabic Treebank: Part 3 v 3.2 (LDC2010T08) (ATB) and to the English treebanked data in English Translation Treebank: An-Nahar Newswire (LDC2012T02).


The source data consists of Arabic newswire from the Lebanese publication An Nahar collected by LDC in 2002. All data is encoded as UTF-8. A count of files, words, tokens and segments is below.

Language Files Words Tokens Segments
Arabic 364 182,351 267,520 7,711

Note: Word count is based on the untokenized Arabic source and token count is based on the ATB-tokenized Arabic source.

The purpose of the GALE word alignment task was to find correspondences between words, phrases or groups of words in a set of parallel texts. Arabic-English word alignment annotation consisted of the following tasks:

  • Identifying different types of links: translated (correct or incorrect) and not translated (correct or incorrect)
  • Identifying sentence segments not suitable for annotation, e.g., blank segments, incorrectly-segmented segments, segments with foreign languages
  • Tagging unmatched words attached to other words or phrases

This release contains four types of files - raw, tokenized, treebank, and wa. The raw format contains the original Arabic and English sentences without any annotation. The tokenized format is the treebank tokenized version of the raw data. It may contain Empty Category tokens (treebank leaves that have the POS label -NONE-). The treebank and wa files are treebank and word alignment annotations on the tokenized files.


Please view the following samples:


This work was supported in part by the Defense Advanced Research Projects Agency, GALE Program Grant No. HR0011-06-1-0003. The content of this publication does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred.


None at this time.

Content Copyright

Portions 2002 An Nahar, 2002-2013 Trustees of the University of Pennsylvania