📖 Automatic Annotation of Direct Speech in Written French Narratives

Automatic Annotation of Direct Speech (AADS) is the task of identifying Direct Speech (DS) text passages from narrative parts. It aims at separating what is uttered by characters inhabiting the storyworld from narrator's words. This repository contains the code of Annotation of Direct Speech in Written French Narratives, accepted for publication to ACL 2023.

Task formalization

We consider AADS as a sequence labeling task that can be solved using literary conventions (regular expressions) or leveraging ML and DL methods trained on annotated novels.

Regular Expression methods serve as baselines for the experiments. Two schemes based on Language Models (LMs) and word-embeddings are adapted for the purpose of these experiments. All models' performances are benchmark on several metrics, either on the whole labels set or aggregated per chapter.

Implemented methods

We benchmark three methods :

• Simple baselines are implemented with regular expression.
• A BiLST-CRF deep learning architecture with to stacked Flair and FastText embeddings.
• Fine-tuned CamemBERT.

Evaluation Schemes

We evaluate performances of each model using:

• Token-level precision, recall, F1 scores
• Span-level precision, recall, F1 scores (Strict Sequence Match)
• Purity/Coverage
• Zone Map Error

Corpus

The experiments showcased in this repository rely on the compilation of four pre-existing corpora of excerpts of public domain french novels published during the XVIII and XIX century.

The fr-litbank and sini-bonus corpora are used as is, SynPaFlex and Straight Talk! corpora were reannotated to fit the chosen framework (ie. annotation of whole chapters with DS labels at the token level).

fr-litbank, sini-bonus and SynPaFlex are considered as the main corpus, while Strait Talk! files are considered as noisy corpus due to its poorer formating quality (lack of breaklines, misplaced breaklines, etc.).

Main corpus statistics are shown in the following table:

	Files	Tokens	Sentences	Av. DS%
Main — train	37	353,658	13,881	40 (30)
Main — val	6	71,739	3,443	35 (21)
Main — test	6	62,825	2,303	30 (22)
Noisy — ST!	38	236,645	10,020	38 (21)
Total	87	724,867	29,647	38 (25)

We provide the raw annotated corpus in json format, available at data/aggregated_corpus.json. We also provide tokenized versions of the corpus in .tsv format in the subsequent subfolders. Note that we also split the main and noisy corpus in train/val/test splits. These files were generated using the following command line:

python preprocess/tokenize_corpus.py --data_dir /src/data/aggregated_corpus.json --output_dir src/data/ --tokenizer [$TOKENIZER]

where the tokenizer variable can be set to spacy_tokenization or nltk_tokenization. The spacy_tokenization was used for all experiments.

🛠 Reproducing results

Installation

This repository requires python $\geq$ 3.8.3. Install dependancies in a fresh virtual environment with:

pip install -r requirements.txt

Install spacy tokenizer fr_core_news_sm with the following command:

python -m spacy download fr_core_news_sm

Runing the benchmark

The following line will train the ML models and compute the performances on both the validation set and the test set:

python run_experiments.py --configs_folder experiments_configs/best_configs/main

Then, next line can be ran, leveraging the previously trained model on noisy corpus:

python run_experiments.py --configs_folder experiments_configs/best_configs/noisy

Models' performance scores are stored as .json files in the results directory following the convention: model_type/tokenization_type/model_name/corpus_type/. Performances on the validation split are stored as val_performances.json and performances on the test split as test_performances.json.

Predicting Direct Speech

The prediction folder presents how to leverage implemented and trained models to predict Direct Speech on unseen texts. The demo_prediction notebook shows steps to preprocess raw text files and predict direct speech.

Clause-consistent predictions

We ran a simple post-processing experiment based on clausse-consistent predictions. We smoothe predictions by clause (through majority vote) to improve the models' performances. Based on prediction .tsv files, smooth predictions are obtained using the following command line:

python post_processing.py --result_path [$RESULT_PATH]

where the variable RESULT_PATH points to the folder containing stored prediction in .tsv format.

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Cite

If you happen to use or modify this code, please remember to cite our paper:

@InProceedings{durandard_directspeech2023,
    title = {Automatic Annotation of Direct Speech in French Narratives},
    booktitle = {Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)},
    author = {Durandard, Noé and
      Tran, Viet Anh and
      Michel, Gaspard and
      Epure, V. Elena},
    year = {2023}
}

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