BOLT English Treebank - SMS/Chat

Item Name: BOLT English Treebank - SMS/Chat
Author(s): Ann Bies, Justin Mott, Colin Warner, Seth Kulick
LDC Catalog No.: LDC2021T03
ISBN: 1-58563-953-2
ISLRN: 240-454-483-982-6
Release Date: January 15, 2021
Member Year(s): 2021
DCMI Type(s): Text
Data Source(s): text chat conversations
Project(s): BOLT
Application(s): automatic content extraction, information detection, machine translation
Language(s): English
Language ID(s): eng
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2021T03 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Bies, Ann, et al. BOLT English Treebank - SMS/Chat LDC2021T03. Web Download. Philadelphia: Linguistic Data Consortium, 2021.
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BOLT English Treebank - SMS/Chat was developed by the Linguistic Data Consortium (LDC) and consists of English SMS and text chat data with part-of-speech and syntactic structure annotation.

The DARPA BOLT (Broad Operational Language Translation) program developed machine translation and information retrieval for less formal genres, focusing particularly on user-generated content. LDC supported the BOLT program by collecting informal data sources -- discussion forums, text messaging and chat -- in Chinese, Egyptian Arabic and English. The collected data was translated and annotated for various tasks including word alignment, treebanking, propbanking and co-reference.

The unannotated English source data is released as BOLT English SMS/Chat (LDC2018T19).

Part-of-speech and treebank annotation conformed to Penn Treebank II style, incorporating changes to those guidelines that were developed under the GALE (Global Autonomous Language Exploitation) program. Those changes primarily concerned the tokenization of hyphenated words, part-of-speech and tree changes necessitated by the tokenization changes, and updates to the syntactic annotation to comply with updated annotation guidelines. Supplementary guidelines for English treebanks and web text are included with this release.


The source data consists of 115,667 tokens/words in 484 files of English SMS and text chat collected by LDC using two methods: new collection via LDC's collection platform and donation of SMS or chat archives from BOLT collection participants. All of the data was annotated for word-level tokenization, part-of-speech, and syntactic structure.

Data is presented in a a variety of UTF-8 encoded text formats, specifically, plain text, XML, and Penn Treebank. See the included documentation for more information about specific formats.


This material is based upon work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract No. HR0011-11-C-0145. The content does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred.


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