Low-Resource POS-Tagging: 2014

Author: Dan Garrette ([email protected])

This is a rewritten version of the code used in the papers:

Learning a Part-of-Speech Tagger from Two Hours of Annotation
Dan Garrette and Jason Baldridge
In Proceedings of NAACL 2013

Real-World Semi-Supervised Learning of POS-Taggers for Low-Resource Languages
Dan Garrette, Jason Mielens, and Jason Baldridge
In Proceedings of ACL 2013

This archive contains code, written in Scala, for training and tagging using the approach described in the papers. You do not need to have Scala installed in order to run the software since Scala runs on the Java Virtual Machine (JVM). Thus, if you have Java installed, you should be able to run the system as described below.

Setting things up

Getting the code

Clone the project:

$ git clone https://github.com/dhgarrette/low-resource-pos-tagging-2014.git

The rest of these instructions assume starting from the low-resource-pos-tagging-2014 directory.

Compile the project

$ ./compile

NOTE: You will need to be connected to the internet the first time you run this since it will need to download several libraries that are required by the code.

Running the system

$ ./run OPTIONS

Training data. If rawFile is given, toksupFile or typesupFile (or both) must be given.

• --rawFile: Location of the unannotated training data.
• --toksupFile: Location of the token-supervision training data: annotated sentences.
• --typesupFile: Location of the type-supervision training data: annotated words (line breaks don't matter; whitespace is ignored).

Model serialization file. Required if training data is not given.

• --modelFile: Location of the saved model file, either for saving after training, or for retrieving if no training data is given.

Data to run the tagger on.

• --inputFile: Location of an unannotated file to tag.
• --outputFile: Output location of the result of tagging the inputFile.
• --evalFile: Location of an annotated file to evaluate on.

Additional options.

• --tdCutoff: Tag dictionary cutoff. Default: none.
• --numRawTokens: Number of raw tokens (complete sentences up to this number of total tokens). Default: infinite.
• --labelPropIterations: Number of iterations for the label propagation procedure. Default 200
• --emIterations: Number of iterations for the HMM EM training procedure. Default 50
• --memmIterations: Number of iterations for the MEMM training procedure. Default 100
• --memmCutoff: Cutoff for number of feature occurrences. Default 100

For example:

$ ./run --rawFile data/raw.txt --toksupFile data/toksup.txt --typesupFile data/typesup.txt --modelFile data/model.ser --memmCutoff 10
$ ./run --modelFile data/model.ser --inputFile data/input.txt --outputFile data/output.txt
$ ./run --modelFile data/model.ser --evalFile data/eval.txt

Note: You should set the JAVA_OPTS environment variable to increase the available memory:

export JAVA_OPTS="-Xmx4g"

Data Format

Unannotated files (rawFile, inputFile) should be whitespace-separated tokens, one sentence per line:

the man chases a cat .
the dog chases a man .

Annotated files (toksupFile, typesupFile, evalFile) should be whitespace-separated tokens, one sentence per line, where each token is word|tag:

the|D man|N sees|V the|D dog|N .|.
the|D dog|N runs|V .|.

Universal Tagset Mappings for Malagasy and Kinyarwanda

For those interested in using Universal POS Tags, please use this mapping, created by Long Duong:

Kinyarwanda

No	Kinyarwanda Tag	Universal Tag	Description
1	,	PUNCT	Comma character
2	.	PUNCT	Dot character
3	ADJ	ADJ	Adjective
4	ADV	ADV	Adverb
5	C	CONJ	Conjunction
6	CC	CONJ	Conjunction
7	DT	DET	Determiner
8	N	NOUN	Noun
9	PREP	ADP	Preposition
10	V	VERB	Verb
11	X	X	Foreign words

Malagasy

No	Malagasy Tag	Universal Tag	Description
1	,	PUNC	Comma character
2	:	PUNC	Semi column character
3	.	PUNC	Dot character
4	...	PUNC	Ellipsis
5	"	PUNC	Quotation character
6	@-@	PUNC	Dash character
7	ADJ	ADJ	Adjective
8	ADV	ADV	Adverb
9	C	CONJ	Conjunction
10	CONJ	CONJ	Conjunction
11	DT	DET	Determiner
12	FOC	DET	Focus Marker (similar to determiner)
13	-LRB-	PUNC	Left Round Bracket
14	N	NOUN	Noun
15	NEG	ADV	Negation
16	PCL	PRT	Particle
17	PN	NOUN	Proper noun
18	PREP	ADP	Preposition
19	PRO	PRON	Pronoun
20	-RRB-	PUNC	Right Round Bracket
21	T	VERB	Passive verb
22	V	VERB	Normal Verb
23	X	X	Foreign root