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ChatDOCx

A domain specific chatbot powered by Hugging Face and Python

An example where the bot answers some sample questions:

ChatDOCx

NOTE: ChatDOCx is experimental and may not work properly. Please provide context-based questions for better results.

Table of Contents

Simple theory

Transformers

  • Transformers are a deep learning model architecture designed for sequential data processing tasks and have revolutionized NLP tasks.
  • They consist of multiple layers of self-attention (which is a key mechanism that enable them to weigh the importance of different input tokens dynamically, capturing long-range dependencies in the data effectively.) and feedforward neural networks.
  • Pre-trained models like BERT, GPT, T5 etc., have been released by major organizations, enabling transfer learning for downstream NLP tasks.

We will use the following models for our chatbot:

RoBERTa for question answering

Facebook AI's RoBERTa (Robustly Optimized BERT Approach) is an improvement to Google AI's BERT (Bidirectional Encoder Representations from Transformers). While BERT laid the foundation for transformer-based models in NLP, RoBERTa further optimized the pre-training process and achieved better performance by leveraging larger datasets and advanced training techniques:

  • Advanced Training Techniques: RoBERTa incorporated techniques such as dynamic masking and increased batch sizes. Dynamic masking involves masking tokens dynamically during pre-training, allowing the model to focus more on learning contextual information. Additionally, RoBERTa used larger mini-batches during training, which helped in better generalization and optimization.

  • Focus on Masked Language Modeling (MLM): Unlike BERT, which also included the next sentence prediction (NSP) task during pre-training, RoBERTa focused solely on the MLM task. By dedicating all resources to improving the accuracy of predicting masked tokens, RoBERTa was able to fine-tune its language understanding capabilities more effectively.

BART for text summarization

BART (Bidirectional and Auto-Regressive Transformers) is a sequence-to-sequence model introduced by Facebook AI:

  • Bidirectional: It can process input sequences in both forward and backward directions. This bidirectional capability enables BART to capture context from both preceding and succeeding tokens, enhancing its understanding of the input sequence.

  • Auto-Regressive: It employs an auto-regressive decoding strategy during generation, where it generates one token at a time from left to right based on the previously generated tokens. This approach ensures that each token is conditioned on the tokens generated before it, allowing it to produce coherent and contextually relevant outputs.

Running the chatbot

Install the dependencies

First up, install all the required Python dependencies by running: pip install -r requirements.txt

NOTE: Development environment is Windows/Python version 3.12.2 (there can always be version conflicts between the dependencies, OS, hardware etc.).

Run the web app

The web application is powered by Flask, run it with: python nlp.py. In the command window, you should see something like WARNING: This is a development server. Do not use it in a production deployment.

  • Running on http:/100.0.1.0:8000

Which is your web adress (just copy paste it in your browser to access the app). Please refer to Features to customize the app.

Features

The following can be configured in mylib/config.json:

{
    "qa_model_name": "deepset/roberta-base-squad2",
    "summary_model_name": "facebook/bart-large-cnn",
    "app_name": "",
    "use_stopwords": true
}
  • qa_model_name is the model used for question answering (RoBERTa).
  • summary_model_name is the model used for text summarization (BART).
  • app_name is optional if you would like to showcase your own branding on the app.
  • use_stopwords will remove the common english words for the models to handle the questions better.

Domains

Setting domains/topics is a core component of the chatbot as it performs better if the data is structured as a single domain, because it will help the bot to remember the context behind the data when asking questions.

Question answering

When you run the app, you are enforced to select a domain to start asking questions, not because you can, but because you get better responses :) So just select a domain, ask your question and then press Enter or click Submit, as seen from the example at the start.

Text summarization

After selecting a domain, simply include the keywords summary or summarize in your input question e.g., summary of transformers, summarize nlp etc., to get a summary of the domain:

ChatDOCx

NOTE: Text summarization appears to be a bit slow. Performance probably depends on the model, the amount of data etc.

Customization

The chatbot can be highly customized as many functions are designed from scratch with flexibility. For instance:

  • Adding data: Data is hosted under data folder as .txt files.
  • Domains/topics: are displayed based on the data (text file name) automatically. Several domains can be created depending on the text files you have in the data folder. The color of a domain can also be changed by modifying the following snippet under templates/ChatDOCx.html:
{% set topic_colors = {'Contacts': '#FFD700', 'Links': '#FFD700', 'Errors': '#f36262'} %}
  • Models: used are tested/selected on the responses they provide, but different models from Hugging Face can be used (see mylib/config.json to configure the model and References section for a list of Hugging Face models).
  • Webapp: is designed from scratch with HTML/JavaScript styling and you can design it as per your wish (see templates folder).
  • Links: can be added under data/links.json. Just select the domain Links and include the keyword link followed by your question e.g., link to transformers.

NOTE: Links are also matched to your questions. In the example below, the keyword transformers in your question is also in the links.json database, which gives you a streamlined answer to learn more about transformers as a clickable link.

  • Contacts: can be added under data/contacts.json. Just select the domain Contacts and include the keyword contact followed by your question e.g., contact of huggingface.
ChatDOCx

Error handling

Errors will be shown on the red bar in the app. Implemented logic to handle domain selection, empty/short inputs, questions outside the scope of chatbot to prevent misinformation. Below is the showcase, including an example where the bot handles questions outside the scope of its knowledge (NOTE: use_stopwords will enhance this function):

ChatDOCx

Future scope

  • Implement RAG (Retrieval-Augmented Generation) to improve domain specific knowledge.
  • Memory function to save the chat history.
  • Function to handle multiple file formats (only supports .txt files atm), or a better way to fetch the data in real-time.

References

saimj7/ 14-04-2024 - © Sai_Mj.