Hurdles to Progress in Long-form Question Answering

This repository contains the official scripts and datasets accompanying our NAACL 2021 paper, "Hurdles to Progress in Long-form Question Answering". This repository supports inference from the pretrained retriever / generator & includes evaluation scripts.

Specifically, this codebase contains the model checkpoints, inference scripts for the retriever / generator model, generated outputs from model using c-REALM retrievals and random retrievals, scripts to compute ROUGE-L / R-Prec scores using the generations, scripts for question paraphrase classification, scripts for computing ROUGE-L bounds. You can also find the original Routing Transformer model's codebase here.


pip install transformers
pip install tensor2tensor

For GPU support, you might need to change the version of your TensorFlow depending on the CUDA / CuDNN installation (details). GPU support is strongly recommended for faster inference.

Model Checkpoints & Generations

Routing Transformer finetuned on ELI5: link
c-REALM TF Hub model + encoded retrieval corpora: link
c-REALM tokenized KILT Wikipedia data: link
c-REALM tokenized ELI5 training data: link
Pre-computed generations & QQP classifier: link

The original Routing Transformer model (pretrained on PG-19) and a local attention version of it can be found in the main repository (link).

Generating from the Routing Transformer

(We have provided the pre-computed retrievals from c-REALM on ELI5, so no need to run the c-REALM retriever)

  1. Download the "Routing Transformer finetuned on ELI5" model listed above and place it inside models.

    unzip -d models

  2. Download the generations folder from the Google Drive link listed as "Pre-computed generations & QQP classifier" above.

  3. Run to generate from the model. We have provided c-REALM retrieval outputs in the script for the ELI5 validation / test split. For custom inputs, you will need to load the retriever and wikipedia corpus (see next section). Generation is on the slower side (~4 minutes per ELI5 QA pair on a 1080ti GPU), we hope to switch to the faster decoding mode in the Routing Transformer model in the near future.

Retrievals from c-REALM

(This script only tests the retriever, it doesn't depend on the Routing Transformer generator model)

  1. Download the "c-REALM TF Hub model + encoded retrieval corpora" model listed above. Place it inside the models folder.

    unzip -d models

  2. Download "c-REALM tokenized KILT Wikipedia data" if you are interested in retrieving from the KILT Wikipedia corpus and/or "c-REALM tokenized ELI5 training data" if you are interested in retrieving question paraphrases from the ELI5 training set. Place them inside the models folder.

    unzip -d models

  3. Run to retrieve using c-REALM. Modify the --retrieval_corpus flag to choose the retrieval corpus.

Evaluation of Outputs


  1. Download the generations folder from the Google Drive link into this root folder.

  2. Clone the KILT repository in this folder and run the installation in a virtual environment.

    git clone
    cd KILT
    virtualenv -p python3.7 kilt-venv
    pip install -r requirements.txt
    pip install --editable .

  3. If you are interested in using the Quora Question Paraphrase classifier (used in Section 3.2 of the paper), download the roberta-large-finetuned-qqp folder from "Pre-computed generations & QQP classifier" listed above. This model was built by Tu Vu.

  4. Download the ELI5 train, validation and test splits.

    cd KILT
    wget -O train.jsonl
    wget -O valid.jsonl
    wget -O test.jsonl

Running evaluations

Enter the KILT folder and run the following command for evaluating p=0.6 with c-REALM retrievals on the validation set:

python kilt/ ../generations/final_guess_eli5_0.6_predicted_retrieval.jsonl ../generations/final_gold_eli5_0.6_predicted_retrieval.jsonl

which should give you the output (partly reported in Table 6 of the paper),

{   'downstream': {   'accuracy': 0.0,
                      'em': 0.0,
                      'f1': 0.25566078582652935,
                      'rougel': 0.24417152125142375},
    'kilt': {   'KILT-accuracy': 0.0,
                'KILT-em': 0.0,
                'KILT-f1': 0.03414819887348917,
                'KILT-rougel': 0.03205580975169385},
    'retrieval': {'Rprec': 0.13258897418004187, 'recall@5': 0.2122586648057688}}

To evaluate other configurations, modify the paths in the command above. You can replace 0.6 with 0.9 for higher entropy generations, and replace predicted with random for randomly selected retrieval paragraphs (Hurdle #1 or Section 3.1 in the paper). Note that you should make this change for both the guess and gold files, to ensure correct alignment. We have only provided generations for the validation set since the test set answers / retrievals for ELI5 are hidden behind the KILT leaderboard.

Question paraphrase classification using QQP Classifier

In Section 3.2 of our paper, we used a Quora Question Paraphrase classifier to find question paraphrases amoung similar questions retrieved by c-REALM. To run this, make sure you have downloaded the QQP checkpoint (step 3 in Setup) and run,

python --input_file generations/final_guess_eli5_0.6_similar_questions.jsonl

You should get a score of 43.6%. Note that this is a lower-bound --- qualitatively we found this classifier missed several paraphrase pairs with low lexical overlap, or cases where the retrieved training set question will have a super-set of the information needed to answer the validation set question.

Lower and Upper Bounds on ROUGE-L

Run the following to evaluate bounds on ROUGE-L. Make sure you have completed steps 1, 4 in the setup above. Scripts to evaluate other bounds involving training set retrieval coming soon!

cp KILT/

# Copy input lowerbound, should get 20.0 ROUGE-L
python --bound_type copy_input

# Random training set answer, should get 15.8-16.2 ROUGE-L depending on randomness
python --bound_type random_train_ans

# "Performance" can be further boosted by randomly selecting from only longest answers
# for each training set question, up to ~16.7 ROUGE-L. This result is not reported in
# paper, but can be run using:
python --bound_type random_train_ans_longest

# Longest gold answer upperbound, should get 21.2 ROUGE-L
python --bound_type longest_gold

# Best gold answer upperbound, should get 26.2 ROUGE-L (takes a while to run, 45 min on single core)
python --bound_type best_gold


If you found our paper or this repository useful, please cite:

author={Kalpesh Krishna and Aurko Roy and Mohit Iyyer},
Booktitle = {North American Association for Computational Linguistics},
Year = "2021",
Title={Hurdles to Progress in Long-form Question Answering},