Arabic Gigaword


Item Name: Arabic Gigaword
Authors: David Graff
LDC Catalog No.: LDC2003T12
ISBN: 1-58563-271-6
Release Date: Jul 22, 2003
Data Type: text
Data Source(s): newswire
Project(s): EARS, GALE, TIDES
Application(s): information retrieval, language modeling, natural language processing
Language(s): Modern Standard Arabic
Language ID(s): arb
Distribution: 1 DVD
Member fee: $0 for 2003 members
Non-member Fee: US $3000.00
Reduced-License Fee: US $1500.00
Extra-Copy Fee: US $200.00
Non-member License: yes
Online documentation: yes
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: David Graff
2003
Arabic Gigaword
Linguistic Data Consortium, Philadelphia

Introduction

Arabic Gigaword was produced by Linguistic Data Consortium (LDC) catalog number LDC2003T12 and ISBN 1-58563-271-6. This is a comprehensive archive of newswire text data that has been acquired from Arabic news sources by the Linguistic Data Consortium (LDC) at the University of Pennsylvania.

Four distinct sources of Arabic newswire are represented here:

Agence France Presse (afa)
Al Hayat News Agency (alh)
Al Nahar News Agency (ann)
Xinhua News Agency (xin)

Much of the AFP content in this collection has been published previously by the LDC in Arabic Newswire Part 1 (LDC2001T55) and some of this content has also been included in an Arabic supplement to TDT3 and as the Arabic component of TDT4. TDT4 also included a four month sample from Al Hayat and An Nahar (October 2000 - January 2001). Apart from that, all of the Al Hayat, An Nahar and Xinhua Arabic content, as well as AFP content for 2001-2002, is being released here for the first time.

Data

There are 319 files, totalling approximately 1.1GB in compressed form (4348 MB uncompressed, and 391619 Kwords).

The table below presents the following categories of information: source of the data, number of files per source, Gzip-MB shows totals for compressed file sizes, Totl-MB shows totals for uncompressed file sizes (i.e. approximately 4.3 gigabytes, total), K-wrds are the number of space-separated tokens in the text, excluding SGML tags.

Source #Files Gzip-MB Totl-MB K-wrds #DOCs
AFA 104 274 1091 94484 516855
ALH 95 431 1535 139501 305250
ANN 96 415 1530 140247 327768
XIA 24 47 192 17387 106846
TOTAL 319 1167 4348 391619 1256719

All text files in this corpus have been converted to UTF-8 character encoding.

Owing to the use of UTF-8, the SGML tagging within each file shows up as lines of single-byte-per-character (ASCII) text, whereas lines of actual text data, including article headlines and datelines, contain a mixture of single-byte and multi-byte characters. In general, single-byte characters in the text data will consist of digits and punctuation marks (where the original source relied on ASCII punctuation codes, rather than Arabic-specific punctuation), whereas multi-byte characters consist of Arabic letters and a small number of special punctuation or other symbols. This variable-width character encoding is intrinsic to UTF-8, and all UTF-8 capable processes will handle the data appropriately.

Each data file name consists of the three-letter prefix, followed by a six-digit date (representing the year and month during which the file contents were generated by the respective news source), followed by a ".gz" file extension, indicating that the file contents have been compressed using the GNU "gzip" compression utility (RFC 1952). So, each file contains all the usable data received by LDC for the given month from the given news source.

All text data are presented in SGML form, using a very simple, minimal markup structure. The corpus has been fully validated by a standard SGML parser utility (nsgmls), using the DTD file provided in the publication.

Unlike older corpora, the present corpus uses only the information structure that is common to all sources and serves a clear function: headline, dateline, and core news content (usually containing paragraphs).

All sources have received a uniform treatment in terms of quality control, and have been categorized into three distinct "types":

story this type of DOC represents a coherent report on a particular topic or event, consisting of paragraphs and full sentences
multi this type of DOC contains a series of unrelated "blurbs," each of which briefly describes a particular topic or event: "summaries of today's news," "news briefs in ... (some general area like finance or sports)," and so on
other these DOCs clearly do not fall into any of the above types; these are things like lists of sports scores, stock prices, temperatures around the world, and so on

The general strategy for categorizing DOCs into these three classes was, for each source, to discover the most common and frequent clues in the text stream that correlated with the "non-story" types. When none of the known clues was in evidence, the DOC was classified as a "story."

Previous "Gigaword" corpora (in English and Chinese) had a fourth category, "advis" (for "advisory"), which applied to DOCs that contain text intended solely for news service editors, not the news-reading public. In preparing the Arabic data, the task of determining patterns for assigning "non-story" type labels was carried out by a native speaker of Arabic. For whatever reason, this person did not find the "advis" category to be applicable to any of the data.

Updates

This edition of Arabic Gigaword has been superseded by a a new edtion, LDC2006T02

Content Copyright

Portions 1994-2002 Agence France Presse, 1994-2001 Al Hayat News Agency, 1995-2002 An Nahar News Agency, 2001-2003 Xinhua News Agency, 2003 Trustees of the University of Pennsylvania