| ==================================================== |
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| CoNLL-2014 Shared Task: Grammatical Error Correction |
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| Description of Preprocessed NUCLE Data Set |
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| 7 April 2014 Version 3.2 |
| ==================================================== |
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| 1. General |
| ========== |
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| This README file describes a preprocessed version of the NUS Corpus of |
| Learner English (NUCLE). For information about NUCLE, please refer to |
| the NUCLE README file. For information about the CoNLL-2014 shared |
| task, please refer to the shared task website. |
|
|
| The preprocessed data set, following earlier CoNLL shared tasks, |
| provides syntactic information for the raw texts in NUCLE. For each |
| sentence, the part of speech tags, dependency parse tree, and |
| constituent parse tree are encoded in a column format. |
|
|
| In NUCLE, annotations are made at the character level, which means |
| both the start offset and the end offset of an error annotation are |
| character positions in the corresponding paragraph. In this |
| preprocessed version, annotations are made at the token level, which |
| means the start offset and the end offset are indexes of tokens in the |
| corresponding sentence. |
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| This README is updated on 4 August 2014. |
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| 2. Files |
| ======== |
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| Two files are to be generated: |
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| conll14st-preprocessed.conll |
| conll14st-preprocessed.conll.ann |
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| conll14st-preprocessed.conll contains the preprocessed data in |
| CoNLL-style column format. This file is not included in this |
| distribution due to the size. |
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| conll14st-preprocessed.conll.ann contains token-level annotations. |
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| 3. Preprocessing systems |
| ======================== |
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| The NUCLE corpus is preprocessed with the following steps to generate |
| this preprocessed data set: |
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| a). sentence splitting, using nltk punkt [1]. |
| Note: the version used to generate the files is before the fixing |
| of issue 514 |
| b). word tokenization, using nltk word_tokenize [1]. |
| c). POS tags, dependency parse trees, and constituent parse trees, |
| using the Stanford parser [2]. |
| d). projecting character-level annotation to token-level annotation. |
|
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| Results from (a-c) are in conll14st-preprocessed.conll. The projected |
| annotations (d) are included in conll14st-preprocessed.conll.ann. |
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| 4. Data format |
| ============== |
|
|
| Here is an example sentence in conll14st-preprocessed.conll: |
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| NID PID SID TOKENID TOKEN POS DPHEAD DPREL SYNT |
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| 829 1 2 0 This DT 1 det (ROOT(S(NP* |
| 829 1 2 1 will NN 7 nsubj *) |
| 829 1 2 2 , , - - * |
| 829 1 2 3 if IN 4 mark (SBAR* |
| 829 1 2 4 not RB 7 dep (FRAG* |
| 829 1 2 5 already RB 4 dep (ADVP*))) |
| 829 1 2 6 , , - - * |
| 829 1 2 7 caused VBD -1 root (VP* |
| 829 1 2 8 problems NNS 7 dobj (NP*) |
| 829 1 2 9 as IN 11 mark (SBAR* |
| 829 1 2 10 there EX 11 expl (S(NP*) |
| 829 1 2 11 are VBP 7 advcl (VP* |
| 829 1 2 12 very RB 13 advmod (NP(NP(ADJP* |
| 829 1 2 13 limited VBN 14 amod *) |
| 829 1 2 14 spaces NNS 11 nsubj *) |
| 829 1 2 15 for IN 14 prep (PP* |
| 829 1 2 16 us PRP 15 pobj (NP*))))))) |
| 829 1 2 17 . . - - *)) |
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| The columns represent the following: |
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| Column Type Description |
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| 0 NID Document id of the sentence, equals to "nid" in NUCLE. |
| 1 PID Paragraph index of the sentence, according to the paragraphing in NUCLE (<p></p>). |
| 2 SID Sentence index in paragraph, each sentence has its own index starting from 0. |
| 3 TOKENID Token index in the sentence, starting from 0. |
| 4 TOKEN Word/token. |
| 5 POS Part of speech tag. |
| 6 DPHEAD Index of parent in dependency tree. |
| 7 DPREL Dependency relation with parent. |
| 8 SYNT Constituent tree. The constituent tree can be recovered as follows: |
| (a) Replacing "*" in this column with a string "(pos word)", |
| where pos is the value of column 5, word is the value of column 4. |
| (b) Concatenating all the strings in (a) gives |
| the bracketing structure of the constituent parse tree. |
|
|
| ------------------------------------------------------------------------ |
| |
| Here is the corresponding token-level annotation for the above |
| sentence (in conll14st-preprocessed.conll.ann): |
| |
| <ANNOTATION> |
| <MISTAKE nid="829" pid="1" sid="2" start_token="7" end_token="8"> |
| <TYPE>Vform</TYPE> |
| <CORRECTION>cause</CORRECTION> |
| </MISTAKE> |
| <MISTAKE nid="829" pid="1" sid="2" start_token="14" end_token="15"> |
| <TYPE>Nn</TYPE> |
| <CORRECTION>space</CORRECTION> |
| </MISTAKE> |
| <MISTAKE nid="829" pid="1" sid="2" start_token="11" end_token="12"> |
| <TYPE>SVA</TYPE> |
| <CORRECTION>is</CORRECTION> |
| </MISTAKE> |
| </ANNOTATION> |
| |
| The tags represent the following: |
| |
| Tag Description |
| |
| <ANNOTATION> Each <ANNOTATION></ANNOTATION> section identifies annotations for one sentence. |
| |
| <MISTAKE> Identifies an error annotation, with the following attributes: |
| nid: Document id of the sentence, equals to the NID column (column 0) in .conll file |
| pid: Paragraph index of the sentence, equals to the PID column in .conll file |
| sid: Sentence index in paragraph, equals to the SID column in .conll file |
| start_token: The token index (TOKENID column in .conll file) which is the start of annotation. |
| end_token: The token index which is the end of the annotation. |
| |
| <TYPE> Error tag (refer to the NUCLE corpus README file for the complete list of error tags). |
| |
| <CORRECTION> Correction, replacing tokens in the interval [start_token, end_token) with the |
| correction string will result in a corrected sentence. |
| |
| ------------------------------------------------------------------------ |
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| How to map a sentence to its annotation? |
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| In conll14st-preprocessed.conll, different sentences are separated by |
| empty lines, and <ANNOTATION></ANNOTATION> sections are also separated |
| by empty lines in conll14st-preprocessed.conll.ann. A sentence maps |
| to one <ANNOTATION></ANNOTATION> section, with the same nid, pid, and |
| sid. If a sentence has no annotation, there is no |
| <ANNOTATION></ANNOTATION> section for it. The order of the |
| <ANNOTATION></ANNOTATION> sections is the same as the order of |
| sentences in the preprocesed file. |
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| 5. Updates included in version 2.1 |
| ================================== |
|
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| The error categories Wcip and Rloc have been mapped to Prep, Wci, |
| ArtOrDet, and Rloc-, to facilitate the detection and correction of |
| preposition errors and article/determiner errors. See the NUCLE README |
| file for details on how the mapping was done. |
|
|
| 50 overlapping error annotations involving the 5 error tags ArtOrDet, |
| Prep, Nn, Vform, and SVA have been modified such that they do not |
| overlap in the revised error annotations. |
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| Some minor mistakes in error annotations have been corrected. |
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| This was done for the CoNLL-2013 Shared Task. |
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| 6. Updates included in version 3.0 |
| ================================== |
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| The overlapping error annotations of the remaining error tags have |
| been modified such that they do not overlap in the revised error |
| annotations. |
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| Some minor mistakes in error annotations have been corrected. |
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| 7. Updates included in version 3.1 |
| ================================== |
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| Duplicate error annotations, each having the same span and correction |
| string but different error type, are removed to keep only one of |
| those. |
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| Previously, annotations spanning to the end of the paragraph was |
| detected as cross-sentence and therefore not included in the |
| preprocessed format. This has been fixed such that they are included |
| in the preprocessed format. |
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| Some minor mistakes in error annotations have been corrected. |
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| 8. Updates included in version 3.2 |
| ================================== |
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| The preprocessing script has been fixed such that gold edits that |
| insert empty string are not included in the token-level gold edit and |
| scorer answer files. |
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| 9. References |
| ============= |
|
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| [1] Steven Bird, Ewan Klein, and Edward Loper. 2009. Natural Language |
| Processing with Python. O'Reilly Media Inc. http://nltk.org/ |
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| [2] Dan Klein and Christopher D. Manning. 2003. Accurate Unlexicalized |
| Parsing. Proceedings of the 41st Annual Meeting of the Association for |
| Computational Linguistics, pp. 423-430. |
| Stanford parser version 2.0.1. |
| http://nlp.stanford.edu/software/stanford-parser-2012-03-09.tgz |
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