Overview

This repository contains the code and sample data for the experiments related to our NAACL 2019 paper "Bridging the Gap: Attending to Discontinuity in Identification of Multiword Expressions".

Prerequisites

pip install -r ./requirements.txt

Run a sample

To check if you have the proper dependencies and see a sample output, simply run main.py. The results (including the predicted labels and the evaluation performance) will be saved in the directory results/{model settings}.

Run your own tagger

Please follow the steps below to run your own model:

1 - Copy your train, test and dev .cupt files under the directory data/{language}/.

2 - Download pre-trained ELMo embeddings.

The models are trained using pre-trained ELMo embeddings. To obtain representations for your inputs, follow the instructions at ELMo For Many Langs. Save the output h5py file (as ELMo_EN, ELMo_FR, etc) and place the files in the ./embeddings folder.

3 - Set all variables (language, tagging model etc) in lines 10-22 of main.py .

4 - run main.py.

Project Structure

In the interest of readability, we provide an overview of the structure of our project:

.
├── README.md
├── corpus.py
├── corpus_reader.py
├── data
│   ├── EN_SAMPLE
│   │   ├── dev.cupt
│   │   ├── test.cupt
│   │   └── train.cupt
│   └── bin
│       ├── evaluate_v1.py
│       └── tsvlib.py
├── embeddings
│   └── ELMo_EN_SAMPLE
├── evaluation.py
├── main.py
├── models
│   ├── layers.py
│   └── tag_models.py
├── preprocessing.py
├── requirements.txt
├── results
└── train_test.py

• corpus.py, and corpus_reader.py: read the data in the conll format and contain methods that is used by the preprocessor.
• embeddings: pre-trained embedding files with the format ELMO_{EN|FR|FA|DE}. It contains a sample file (ELMo_EN_SAMPLE) for the trial run.
• evaluation.py: contains the script for evaluation.
• preprocessing.py: prepares data in the proper format and loads ELMo embeddings.
• layers.py: self-attention, GCN, and highway layers are defined here.
• tag_models.py: our models are all defined here. This part depends on layers.py.
• train_test.py: contains the functions for training and testing the models.
• main.py: the main part connesting all the other scripts. You can specify the main variables here (language, epochs, model, ...).
• data: contains sample data (in EN_SAMPLE) including 5, 2 and 4 sentences in train, dev and test respectively for a trial run. To obtain the data used in the experiments, download train, test, and dev files for each language from Parseme's gitlab page.
• bin: contains the evaluation code of the PARSEME shared task on identifying VMWEs.
• requirements.txt: contains the names and versions of the required dependencies.
• results: results appear here after main.py is run.

TL;DR

If you only care about the model architecture, have a look at ./models/tag_models. Self-attention and GCN are defined in the separate file ./models/layers.py.

Reference

@inproceedings{Rohanian2019,
  author    = {Omid Rohanian and
               Shiva Taslimipoor and
               Samaneh Kouchaki and
               Le An Ha and
               Ruslan Mitkov},
  title     = {Bridging the Gap: Attending to Discontinuity in Identification of
               Multiword Expressions},
  year      = {2019},
  booktitle = {Proceedings of the 2019 Conference of the North {A}merican Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)},
  url       = {https://www.aclweb.org/anthology/N19-1275/},
  pages = "2692--2698",
  abstract = "We introduce a new method to tag Multiword Expressions (MWEs) using a linguistically interpretable language-independent deep learning architecture. We specifically target discontinuity, an under-explored aspect that poses a significant challenge to computational treatment of MWEs. Two neural architectures are explored: Graph Convolutional Network (GCN) and multi-head self-attention. GCN leverages dependency parse information, and self-attention attends to long-range relations. We finally propose a combined model that integrates complementary information from both, through a gating mechanism. The experiments on a standard multilingual dataset for verbal MWEs show that our model outperforms the baselines not only in the case of discontinuous MWEs but also in overall F-score."
}