These are the files used to create the English-to-Dutch tree alignment model using the tree-to-tree aligner Lingua-Align, for the Parse and Corpus-Based Machine Translation (PaCo-MT) project. It consists of 150 pre-processed parallel sentences from the Europarl corpus. We include a gold standard file as well as a file containing only the word alignments. The treebank files to which the alignments refer are also included.

- Sentences were aligned using Hunalign.
- The words were aligned using the bidirectional alignments from GIZA++, trained on the whole Europarl parallel corpus and post-processed with Moses using the intersection of the directions to produce confident alignments and the "grow-diag" alignments (those that are not in the intersection) to produce less confident alignments, in order to increase the recall. However, we have manually corrected the word alignments. By convention, confident alignments are assigned a probability of 0.8 and less confident alignments a probability of 0.4 in the alignment files. A script was used to convert the word alignments to the format used for our tree alignment experiments.
- The Dutch trees were parsed using Alpino.
- The English trees were parsed using the Stanford parser.
- Scripts were used to convert the trees from their native format to TIGER-XML, which is the format required by the Stockholm TreeAligner, the tool which we used to create the manual tree alignments.
- The gold standard was not checked for accuracy by other parties. It may therefore contain some errors.

The following files are included:

- paco-en-nl_150.xml: The gold standard file containing the tree alignments. This is in a format that can be read by the Stockholm TreeAligner and our scripts.
- paco-en-nl_150.wordalign.xml: The same as above, but containing only the word alignments. This might be useful if users would want to create their own gold standards or run their own experiments, for comparative purposes or otherwise.
- ep-00-12-15.150.en.tiger.xml: The English treebank in TIGER-XML format. It is read by the first two files as the source-side treebank.
- ep-00-12-15.150.nl.tiger.xml: The Dutch treebank in TIGER-XML format. It is read by the first two files as the target-side treebank.
- en-nl-training_150: The model learned by Lingua-Align that was applied in the PaCo-MT project, using the above files.
- en-nl-training_150.feat: The features used to train the model.

ep-00-12-15 refers to the date on which the proceedings were recorded, which is the 15th of December of the year 2000.

In the Stockholm TreeAligner, confident ("good") links are displayed as green lines, while the less confident ("fuzzy") links are displayed as red lines. For more information on how to build your own training data and run experiments, we refer the reader to the URLs displayed below.

Sources:

Lingua-Align:
http://stp.lingfil.uu.se/~joerg/Lingua

Stockholm TreeAligner:
http://www.cl.uzh.ch/research/paralleltreebanks/treealigner_en.html

GIZA++:
https://code.google.com/p/giza-pp

Moses:
http://statmt.org/moses

Hunalign:
http://mokk.bme.hu/resources/hunalign

For any questions, please contact the author at:
gidi8ster@gmail.com

Gideon Kotzé
7 July 2013
