OpinionDigest

This repository contains the codebase of our paper OpinionDigest A Simple Framework for Opinion Summarization accepted at ACL 2020.

OpinionDigest is an unsupervised opinion summarization framework that generates a summary from multiple review documents without requiring any gold-standard summary. OpinionDigest relies on an aspect-based sentiment classification model, which extracts opinions from input reviews, to train a seq2seq model that generates a summary from a set of opinions. This framework enables the user to easily control the output by filtering input opinions using aspects and/or sentiment polarity.

Please see our paper for details. Please also try our online demo.

This project is a collaboration with the Natural Language Processing Group at the University of Edinburgh (EdinburghNLP).

Installation

$ git clone https://github.com/megagonlabs/opiniondigest.git
$ cd opiniondigest
$ pip install -r requirements.txt

Preprocessing

To run our framework, you need to preprocess your dataset and extract opinion phrases from the input sentences. You can use any ABSA models to perform the extraction task.

For our experiment on Yelp dataset, we used this extractor (Snippext) to extract opinions from the reviews.

Please follow our example to format your extraction files.

Running

The workflow has following 4 steps. You can configure the settings of each step by creating JSON file.

• Step 1. Data preparation
• Step 2. Training
• Step 3. Aggregation
• Step 4. Generation

You can skip Steps 1-3 by downloading our pre-trained model and dataset.

Step 1. Data preparation

$ python src/prepare.py \
  config/prepare_{p_name}.json

The script will create training/development/test datasets.

$ ls data/{p_name}
train.csv
dev.csv
test.csv

Step 2. Training

To train a model, run the following script with configurations files for preparation and training.

$ python src/train.py \
  config/prepare_{p_name}.json \
  config/train_{t_name}.json

The training script saves following model files.

$ ls model
{p_name}_op2text_{t_name}.model
{p_name}_op2text_{t_name}_IN_TEXT.field
{p_name}_op2text_{t_name}_OUT_TEXT.field
{p_name}_op2text_{t_name}_ID.field

Step 3. Aggregation

$ python src/aggregate.py \
  config/aggregate_{a_name}.json \
  config/prepare_{p_name}.json \
  config/train_{t_name}.json

The script generates following three files.

$ ls data/{p_name}
aggregate_{a_name}.csv

Here p_name needs to be specified in the configuration file aggregate_{a_name}.json. a_name is generated from the parameters _n_k_att_pol:

• n is the number of reviews;
• k is the top-k frequent extractions;
• att is the attribute of the extractions;
• pol is the sentiment polarity of the extractions.

Step 4. Generation

To generate summaries using OpinionDigest model, run the command below:

$ python src/generate.py \
  config/prepare_{p_name}.json \
  config/train_{t_name}.json \
  config/aggregate_{a_name}.json \
  config/generate_{g_name}.json

This will creates following output and log files.

$ ls output
{p_name}_op2text_{t_name}_{g_name}.csv
{p_name}_op2text_{t_name}_{g_name}.log

Evaluation

$ python src/evaluate.py \
  config/prepare_yelp-default.json \
  config/train_tiny.json \
  config/aggregate_default.json \
  config/generate_beam.json

$ cat output/default_op2text_default_greedy.eval
bleu,0.06273896942347468
rouge_1,0.4166751301989266
rouge_2,0.1566288226261539
rouge_l,0.2938877832779797

Reproducing Results on the Yelp dataset

Downloading Data and Pre-trained model

Please make sure to download the data and pre-trained model using the following script.

$ ./download.sh

The script downloads the following files.

├── data
│   └── yelp-default
│       ├── dev.csv
│       ├── summaries_0-200_cleaned_fixed_business_ids.csv
│       ├── test.csv
│       ├── test_gold.csv
│       ├── test_gold_8_15_all_all_300_8.csv
│       ├── train.csv
│       └── yelp.jsonl
└── model
    ├── yelp-default_op2text_default.pt
    ├── yelp-default_op2text_default_ID.field
    ├── yelp-default_op2text_default_IN_TEXT.field
    └── yelp-default_op2text_default_OUT_TEXT.field

• {train|dev|test}.csv: Training/development/test data for train.py
• summaries_0-200_cleaned_fixed_business_ids.csv: Processed version of gold-standard summaries of the Yelp dataset, originally created by MeanSum. We further cleaned the business_ids for easier processing. The original data can be found here.
• test_gold.csv: This file contains input reviews, extractions, and gold-standard summary for each entity.
• test_gold_8_15_all_all_300_8.csv: This file contains aggregated opinion phrases based on test_gold.csv using aggregate.py (please see below)
• yelp.jsonl: This file contains opinion extractions for 1.038M reviews from the Yelp dataset (extracted by Snippext)
• model/: Trained OpinionDigest model (PyTorch checkpoint) and vocabulary files ("pickled" torchtext objects) for tokenizer that are used for the experiments in the paper.

Preprocessing & Training (Optional).

You can follow the instructions above to preprocess the data and train an OpinionDigest model by yourself, or you can directly use the pre-trained model.

Aggregation

Properly prepare the configuration file, and make sure you use test_gold.csv as the input file and summaries_0-200_cleaned_fixed_business_ids.csv as the gold standard summary.

Example:

{ 
  "p_name": "default_yelp", // source directory
  "files": ["test_gold.csv"], // input files
  "gold": "summaries_0-200_cleaned_fixed_business_ids.csv", // gold standard summary
  "embedding": "glove-wiki-gigaword-300", // embedding
  "threshold": 0.8, // similarity threshold
  "num_review": 8, // number of reviews to summarize
  "is_exact": "False", // whether it is ok to have fewer number of reviews
  "top_k": 10, // top-k extractions to summarize
  "sentiment": "all", // selection rule for sentiment, "pos"/"neg"/"all", "" means select everything
  "attribute": "all" // selection rule for attribute, <attr_name>/"all", "" means select everything
}

Use the following command to aggregate opinion extractions:

$ python src/aggregate.py \
  config/aggregate_{a_name}.json \
  config/prepare_{p_name}.json \
  config/train_{t_name}.json

Generation & Evaluation

Follow the steps described above to generate and evaluate summaries.

Citation

@inproceedings{suhara-etal-2020-opiniondigest,
    title = "{O}pinion{D}igest: A Simple Framework for Opinion Summarization",
    author = "Suhara, Yoshihiko and Wang, Xiaolan and Angelidis, Stefanos and Tan, Wang-Chiew",
    booktitle = "Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics",
    year = "2020",
    url = "https://www.aclweb.org/anthology/2020.acl-main.513",
    doi = "10.18653/v1/2020.acl-main.513",
    pages = "5789--5798"
}

*The first two authors contributed equally.