ferret is Python library that streamlines the use and benchmarking of interpretability techniques on Transformers models.

• Documentation: https://ferret.readthedocs.io
• Paper: https://aclanthology.org/2023.eacl-demo.29/
• Demo: https://huggingface.co/spaces/g8a9/ferret

ferret is meant to integrate seamlessly with 🤗 transformers models, among which it currently supports text models only. We provide:

• 🔍 Four established interpretability techniques based on Token-level Feature Attribution. Use them to find the most relevant words to your model output quickly.
• ⚖️ Six Faithfulness and Plausibility evaluation protocols. Benchmark any token-level explanation against these tests to guide your choice toward the most reliable explainer.

ACL Anthology Bibkey:

attanasio-etal-2023-ferret

📝 Examples

All around tutorial (to test all explainers, evaluation metrics, and interface with XAI datasets): Colab

Text Classification

• Intent Detection with Multilingual XLM RoBERTa: Colab

Getting Started

Installation

For the default installation, which does not include the dependencies for the speech XAI functionalities,

pip install -U ferret-xai

Our main dependencies are 🤗 tranformers and datasets.

If the speech XAI functionalities are needed, then

pip install -U ferret-xai[speech]

At the moment, the speech XAI-related dependencies are the only extra ones, so installing with ferret-xai[speech] or ferret-xai[all] is equivalent.

Important Some of our dependencies might use the package name for scikit-learn and that breaks ferret installation.
If your pip install command fails, try:

SKLEARN_ALLOW_DEPRECATED_SKLEARN_PACKAGE_INSTALL=True pip install -U ferret-xai

This is hopefully a temporary situation!

Explain & Benchmark

The code below provides a minimal example to run all the feature-attribution explainers supported by ferret and benchmark them on faithfulness metrics.

We start from a common text classification pipeline

from transformers import AutoModelForSequenceClassification, AutoTokenizer
from ferret import Benchmark

name = "cardiffnlp/twitter-xlm-roberta-base-sentiment"
model = AutoModelForSequenceClassification.from_pretrained(name)
tokenizer = AutoTokenizer.from_pretrained(name)

Using ferret is as simple as:

bench = Benchmark(model, tokenizer)
explanations = bench.explain("You look stunning!", target=1)
evaluations = bench.evaluate_explanations(explanations, target=1)

bench.show_evaluation_table(evaluations)

Be sure to run the code in a Jupyter Notebook/Colab: the cell above will produce a nicely-formatted table to analyze the saliency maps.

Features

ferret offers a painless integration with Hugging Face models and naming conventions. If you are already using the transformers library, you immediately get access to our Explanation and Evaluation API.

Post-Hoc Explainers

• Gradient (plain gradients or multiplied by input token embeddings) (Simonyan et al., 2014)
• Integrated Gradient (plain gradients or multiplied by input token embeddings) (Sundararajan et al., 2017)
• SHAP (via Partition SHAP approximation of Shapley values) (Lundberg and Lee, 2017)
• LIME (Ribeiro et al., 2016)

Evaluation Metrics

Faithfulness measures:

• AOPC Comprehensiveness (DeYoung et al., 2020)
• AOPC Sufficiency (DeYoung et al., 2020)
• Kendall's Tau correlation with Leave-One-Out token removal. (Jain and Wallace, 2019)

Plausibility measures:

• Area-Under-Precision-Recall-Curve (soft score) (DeYoung et al., 2020)
• Token F1 (hard score) (DeYoung et al., 2020)
• Token Intersection Over Union (hard score) (DeYoung et al., 2020)

See our paper for details.

Visualization

The Benchmark class exposes easy-to-use table visualization methods (e.g., within Jupyter Notebooks)

bench = Benchmark(model, tokenizer)

# Pretty-print feature attribution scores by all supported explainers
explanations = bench.explain("You look stunning!")
bench.show_table(explanations)

# Pretty-print all the supported evaluation metrics
evaluations = bench.evaluate_explanations(explanations)
bench.show_evaluation_table(evaluations)

Dataset Evaluations

The Benchmark class has a handy method to compute and average our evaluation metrics across multiple samples from a dataset.

import numpy as np
bench = Benchmark(model, tokenizer)

# Compute and average evaluation scores one of the supported dataset
samples = np.arange(20)
hatexdata = bench.load_dataset("hatexplain")
sample_evaluations =  bench.evaluate_samples(hatexdata, samples)

# Pretty-print the results
bench.show_samples_evaluation_table(sample_evaluations)

Planned Developement

See the changelog file for further details.

• ✅ GPU acceleartion support for inference (v0.4.0)
• ✅ Batched Inference for internal methods's approximation steps (e.g., LIME or SHAP) (v0.4.0)
• ⚙️ Simplified Task API to support NLI, Zero-Shot Text Classification, Language Modeling (branch).
• ⚙️ Multi-sample explanation generation and evaluation
• ⚙️ Support to explainers for seq2seq and autoregressive generation through inseq.
• ⚙️ New evaluation measure: Sensitivity, Stability (Yin et al.)
• ⚙️ New evaluation measure: Area Under the Threshold-Performance Curve (AUC-TP) (Atanasova et al.)
• ⚙️ New explainer: Sampling and Occlusion (SOC) (Jin et al., 2020)
• ⚙️ New explainer: Discretized Integrated Gradient (DIG) (Sanyal and Ren, 2021)
• ⚙️ New explainer: Value Zeroing (Mohebbi et al, 2023)
• ⚙️ Support additional form of aggregation over embeddings' hidden dimension.

Authors

• Giuseppe Attanasio
• Eliana Pastor
• Debora Nozza
• Chiara Di Bonaventura

Credits

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

• Cookiecutter: https://github.com/audreyr/cookiecutter
• audreyr/cookiecutter-pypackage

Logo and graphical assets made by Luca Attanasio.

If you are using ferret for your work, please consider citing us!

@inproceedings{attanasio-etal-2023-ferret,
    title = "ferret: a Framework for Benchmarking Explainers on Transformers",
    author = "Attanasio, Giuseppe and Pastor, Eliana and Di Bonaventura, Chiara and Nozza, Debora",
    booktitle = "Proceedings of the 17th Conference of the European Chapter of the Association for Computational Linguistics: System Demonstrations",
    month = may,
    year = "2023",
    publisher = "Association for Computational Linguistics",
}