SQuAD – Albert

Albert model with SQuAD dataset


The SQuAD dataset is a collection of question-answer pairs, where the answer to each question is a contiguous span of text from the corresponding context paragraph. The Albert model is a neural network model that can be trained to predict the answer to a question given the context paragraph. This project implements the Albert algorithm using the SQuAD dataset.

Using Tensorleap we can explore the latent space, easily detect unlabeled clusters, and handle those with high loss.

This quick start guide will walk you through the steps to get started with this example repository project.

Population Exploration

Below is a population exploration plot. It represents a samples similarity map based on the model’s latent space, built using the extracted features of the trained model.

It shows a visualization of the training and validation sets where we can see two distinct clusters. This means there is a difference in their representation that might indicate some sort of imbalance.

Detecting & Handling High Loss Clusters

In Question Answering (QA), the “title” refers to the title of the passage from which the question is derived, one of the titles in the dataset is ‘American Idol’. Further analysis reveals that a cluster in samples related to the ‘American Idol’ title, has a higher loss (larger dot sizes). At a glance, we can see that this cluster contains questions that relate to the names of songs, such as “What was [singer’s name] first single?” or “What is the name of the song…?”.


It appears that the model did detect the correct answers. However, the prediction contains quotation marks while the ground truth doesn’t.

Detecting Unlabeled Clusters in the Latent Space

Now, let’s look for additional clusters in our data using an unsupervised clustering algorithm on the model’s latent space. Upon examination of these clusters, we can see that clusters 13 and 20, located close to each other, contain answers relating to years and dates of events. Cluster 20 (left side image) includes primarily questions that require answers related to years, such as “What year…?” where the answers are years represented in digits: “1943”, “1659” etc. Cluster 13 (right side image), includes questions that require answers related to dates and times, such as “When.. ?” and answers of the dates and times represented in text and digits: “early months of 1754”, “1 January 1926”, “20 December 1914”, “1990s” etc.

Fetching similar samples

Another approach to finding clusters using the model’s latent space is fetching similar samples to a selected sample. It enables you to identify a cluster with an intrinsic property you want to investigate. By detecting this cluster, you can gain insights into how the model interprets this sample and, in general, retrieve clusters with more abstract patterns.

The figure below shows a Quantitative Questions and Answers cluster. We can see that the cluster which includes quantitative questions and answers contains questions such as “How many …?”, “How often…?”, “How much …?” and answers represented in digits and in words: “three”, “two”, “75%”, “50 million”, “many thousands”.

Sample Loss Analysis

In this section, we can see the results of a gradient-based explanatory algorithm to interpret what drives the model to make specific predictions. It enables us to analyze which of the informative features contributes most to the loss function. We then generate a heatmap with these features that shows the relevant information.

Let’s analyze the following sample containing the question: “when did Beyonce release ‘formation’?”. The correct predicted answer is: “February 6, 2016”. We see that the tokens that had the most impact on the model’s prediction are: ‘when’, ‘one’, ‘day’, ‘before’. Also, the answer tokens:’ February’, ‘6’,’ 2016′.

False / Ambiguous Labelings

The figure below shows an example for illustrates inaccurate and mislabeled samples. We can see a sample with the question (shown in purple): “Did Tesla graduate from the university?” The answer from the context is: “he never graduated from the university” (shown in orange). This was detected correctly by the model. However, the ground truth’s indexes refer to “no” (shown in green) in the sentence: “no Sundays or holidays…”. As in the above example, the indexes are incorrect and in an unrelated location to the question.
![False / Ambiguous Labelings](images/Ambiguous Labelings.png)
Such cases distort the model’s performance and negatively affect its fitting when penalizing the model on these samples. We can solve these issues by changing the ground truth or by removing such samples.

Getting Started with Tensorleap Project

This quick start guide will walk you through the steps to get started with this example repository project.

Prerequisites

Before you begin, ensure that you have the following prerequisites installed:

Tensorleap CLI Installation

with curl:

curl -s https://raw.githubusercontent.com/tensorleap/leap-cli/master/install.sh | bash

Tensorleap CLI Usage

Tensorleap Login

To login to Tensorleap:

tensorleap auth login [api key] [api url].

How To Generate CLI Token from the UI

  1. Login to the platform in ‘CLIENT_NAME.tensorleap.ai’
  2. Scroll down to the bottom of the Resources Management page, then click GENERATE CLI TOKEN in the bottom-left corner.
  3. Once a CLI token is generated, just copy the whole text and paste it into your shell.

Tensorleap Project Deployment

To deploy your local changes:

leap project push

Tensorleap files

Tensorleap files in the repository include leap_binder.py and leap.yaml. The files consist of the required configurations to make the code integrate with the Tensorleap engine:

leap.yaml

leap.yaml file is configured to a dataset in your Tensorleap environment and is synced to the dataset saved in the environment.

For any additional file being used, we add its path under the include parameter:

include:
    - leap_binder.py
    - squad_albert/configs.py
    - [...]

leap_binder.py file

leap_binder.py configures all binding functions used to bind to Tensorleap engine. These are the functions used to evaluate and train the model, visualize the variables, and enrich the analysis with external metadata variables

Testing

To test the system we can run leap_test.py file using poetry:

poetry run test

This file will execute several tests on leap_binder.py script to assert that the implemented binding functions: preprocess, encoders, metadata, etc, run smoothly.

For further explanation please refer to the docs.

Find out more about how Tensorleap can answer your needs. Click here.

Inspected models

1

Dataset

SQuAD

Task

Question Answering

Data Type

Text

Storage

Vertical

NLP

Picture of Danielle Ben Bashat
Danielle Ben Bashat

Data Scientist