NIST 2009 Open Machine Translation (OpenMT) Evaluation

Item Name: NIST 2009 Open Machine Translation (OpenMT) Evaluation
Author(s): NIST Multimodal Information Group
LDC Catalog No.: LDC2010T23
ISBN: 1-58563-570-7
ISLRN: 264-294-098-796-0
Release Date: December 20, 2010
Member Year(s): 2010
DCMI Type(s): Text
Data Source(s): weblogs, newswire
Project(s): NIST MT
Application(s): machine translation
Language(s): Urdu, Arabic
Language ID(s): urd, ara
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2010T23 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: NIST Multimodal Information Group. NIST 2009 Open Machine Translation (OpenMT) Evaluation LDC2010T23. Web Download. Philadelphia: Linguistic Data Consortium, 2010.
Related Works: View


NIST 2009 Open Machine Translation (OpenMT) Evaluation contains source data, reference translations and scoring software used in the NIST 2009 OpenMT evaluation. It is designed to help evaluate the effectiveness of machine translation systems. The package was compiled and scoring software was developed by researchers at NIST, making use of broadcast, newswire and web data and reference translations collected and developed by the Linguistic Data Consortium (LDC).

The objective of the NIST Open Machine Translation (OpenMT) evaluation series is to support research in, and help advance the state of the art of, machine translation (MT) technologies -- technologies that translate text between human languages. Input may include all forms of text. The goal is for the output to be an adequate and fluent translation of the original.

The MT evaluation series started in 2001 as part of the DARPA TIDES (Translingual Information Detection, Extraction) program. Beginning with the 2006 evaluation, the evaluations have been driven and coordinated by NIST as NIST OpenMT. These evaluations provide an important contribution to the direction of research efforts and the calibration of technical capabilities in MT. The OpenMT evaluations are intended to be of interest to all researchers working on the general problem of automatic translation between human languages. To this end, they are designed to be simple, to focus on core technology issues and to be fully supported. The 2009 task was to evaluate translation from Arabic to English and Urdu to English.

Additional information about these evaluations may be found at the NIST Open Machine Translation (OpenMT) Evaluation web site.

Scoring Tools

This evaluation kit includes a single Perl script ( that may be used to produce a translation quality score for one (or more) MT systems. The script works by comparing the system output translation with a set of (expert) reference translations of the same source text. Comparison is based on finding sequences of words in the reference translations that match word sequences in the system output translation. More information on the evaluation algorithm may be obtained from the paper detailing the algorithm: BLEU: a Method for Automatic Evaluation of Machine Translation (Papineni et al, 2002).

The included scoring script is intended for use with SGML-formatted data files. An updated scoring software package (mteval-v13a-20091001.tar.gz), with XML support, additional options and bug fixes, documentation, and example translations, may be downloaded from the NIST Multimodal Information Group Tools website.


This release contains 373 documents with corresponding sets of four separate human expert reference translations. The source data is comprised of Arabic and Urdu broadcast, newswire and weblog data collected by LDC in 2007 and 2009. The newswire and broadcast material are from Asharq Al-Awsat (Arabic), Agence France-Presse (Arabic), Al-Ahram (Arabic), Al Hayat (Arabic), Assabah (Arabic), An Nahar (Arabic), Al-Quds Al-Arabi (Arabic), Xinhua News Agency (Arabic), British Broadcasting Corporation (Urdu), Deutsche Welle (Urdu), Mehr News Agency (Urdu) and Voice of America (Urdu).

For each language, the test set consists of two files: a source and a reference file. Each file contains four independent translations of the data set. The evaluation year, source language, test set (which, by default, is evalset), version of the data, and source vs. reference file (with the latter being indicated by -ref) are reflected in the file name. A reference file contains four independent reference translations unless noted otherwise in the accompanying README.txt.

DARPA TIDES MT and NIST OpenMT evaluations used SGML-formatted test data until 2008 and XML-formatted test data thereafter. This files in this package are provided in both formats.


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Additional information, updates, bug fixes may be available in the LDC catalog entry for this corpus at LDC2010T23.

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