ACE-2 Version 1.0

Item Name: ACE-2 Version 1.0
Author(s): Alexis Mitchell, Stephanie Strassel, Mark Przybocki, JK Davis, George R. Doddington, Ralph Grishman, Adam Meyers, Ada Brunstein, Lisa Ferro, Beth Sundheim
LDC Catalog No.: LDC2003T11
ISBN: 1-58563-270-8
ISLRN: 498-363-793-174-9
Release Date: September 02, 2003
Member Year(s): 2003
DCMI Type(s): Text
Data Source(s): broadcast news, newswire
Project(s): ACE, GALE, TIDES
Application(s): automatic content extraction, information detection
Language(s): English
Language ID(s): eng
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2003T11 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Mitchell, Alexis, et al. ACE-2 Version 1.0 LDC2003T11. Web Download. Philadelphia: Linguistic Data Consortium, 2003.
Related Works: View


ACE-2 Version 1.0 was developed by the Linguistic Data Consortium (LDC) to support the Automatic Content Extraction (ACE) program. The objective of the ACE program was to develop extraction technology to support automatic processing of source language data (in the form of natural text, and as text derived from ASR and OCR). This included classification, filtering, and selection based on the language content of the source data, i.e., based on the meaning conveyed by the data. Thus the ACE program required the development of technologies that automatically detect and characterize this meaning. ACE research objectives were viewed as the detection and characterization of Entities, Relations, and Events. There were three main ACE tasks: Entity Detection and Tracking, Relation Detection and Characterization, and Event Detection and Characterization.

Annotations for the ACE-2 corpus were produced by LDC to support the Entity Detection and Tracking and Relation Detection and Characterization tasks.

For information regarding the ACE program and ACE technology evaluations administered by the National Institute of Standards and Technology (NIST), visit the NIST website.

For information about ACE annotation and ongoing ACE corpus development, including annotation guidelines, task definitions, annotation tools and other project documentation, see LDC's ACE webpage.


This publication contains two sets of data: training and devtest. Each of these sets is further divided by source: broadcast news, newspaper, and newswire.

The training contains data originally developed as training material for the February 2002 evaluation and again for the September 2002 evaluation. The devtest contains data originally developed as test data for the February 2002 evaluation and later used as devtest data for the September 2002 evaluation.

The broadcast and newswire source data was drawn from a subset of the TDT2 Multilanguage Text Version 4.0 (LDC2001T57); this has been supplemented with additional newspaper data from the Washington Post. A portion of the training broadcast data was drawn from the 1997 English Broadcast News Transcripts (HUB4) corpus (LDC98T28).

All material comes from the first half of 1998. The sources for the broadcast, newswire, and newspaper data are listed below.

Newswire New York Times Newswire Service (NYT)
Associated Press Worldstream Service (APW)
Broadcast News Cable News Network, "Headline News" (CNN for TDT2, ed for Hub-4)
American Broadcasting Co., "World News Tonight" (ABC for TDT2, ea for Hub-4)
Public Radio International, "The World" (PRI)
Voice of America, English news programs (VOA)
MSNBC, "The News With Brian Williams" (MNB)
National Broadcasting Company, "Nightly News" (NBC)
Newspaper Washington Post (WAP)

This publication includes both the source data files in .sgm format and the annotation files in ACE Pilot Format (APF), supporting documentation, and version 2.0.1 of the ACE DTD which was used for the September 2002 ACE Evaluation.

There are 179,007 words of source data, or 519 files, broken down as follows:

Source # Words train # Words devtest # Files train # Files devtest
NYT 32892 7487 48 9
APW 29144 7037 82 20
CNN 2290 2653 69 11
ABC 1588 2687 24 10
PRI 1272 5284 43 9
VOA 594 2611 24 7
MNB 0 2539 0 6
NBC 0 2633 0 8
WAP 60247 15070 76 17
ea 2019 0 31 0
ed 1094 0 25 0
Total 131023 47984 422 97


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