From Words to Graphs: How Deep Graph Learning is Revolutionising NLP

ADITYA VERMA
DataX Journal
Published in
12 min readNov 17, 2023

Deep graph learning is a hammer, and NLP is a nail. But the nail is kind of a strange shape, so it’s not always clear how to use the hammer most effectively. — Anonymous

Imagine a world where your favourite digital assistant can understand not just your words, but the subtle nuances and emotions behind them. A world where language barriers crumble effortlessly as you converse with friends from different corners of the globe, and complex documents are summarised instantly, making information accessible at a glance. This transformation isn’t the work of magic, but rather the powerful synergy of NLP and a revolutionary technology — deep graph learning. In this blog, we’ll embark on a journey from words to graphs and discover how this cutting-edge approach is reshaping the future of Natural Language Processing (NLP).

Readers can expect to gain insights into the transformative potential of deep graph learning in Natural Language Processing (NLP). This blog explores the synergy between NLP and deep graph learning, explains the advantages, state-of-the-art models, potential applications, challenges, and opportunities in this evolving field.

Introduction

Natural language processing (NLP) represents a crucial subfield of computer science that focuses on the interaction between computers and human language. NLP encompasses a wide range of tasks, including machine translation, question answering, and text summarization. In recent years, deep graph learning has emerged as a powerful machine learning technique capable of modelling and learning from graph-structured data. Graphs offer a versatile means of representing data with intricate relationships between various components.

This blog post delves into the synergy between deep graph learning and NLP, exploring how deep graph learning can enhance NLP applications. We will also review some of the latest state-of-the-art deep graph learning models tailored for NLP tasks.

What is NLP ?

Natural Language Processing (NLP) is a dynamic field at the intersection of artificial intelligence and linguistics, revolutionizing the way computers understand and interact with human language. It empowers machines to comprehend, interpret, and generate human language, enabling applications such as chatbots, sentiment analysis, and machine translation. NLP algorithms process vast amounts of textual data, extracting meaningful insights and patterns. With the advent of deep learning techniques like neural networks, NLP has made significant strides in speech recognition, language generation, and even understanding context and sentiment. As NLP continues to advance, it holds the potential to enhance communication between humans and machines, making technology more intuitive and accessible than ever before.

Source: Top 5 Semantic Technology Trends to Look for in 2017 (ontotext).

Why Use Graphs for NLP?

Graphs are a powerful tool for modeling the complex relationships between words and sentences in natural language. This makes them well-suited for a variety of NLP tasks, including machine translation, question answering, and text summarization.

One advantage of using graphs for NLP is that they can be used to learn unsupervisedly. This means that graphs can be constructed from raw text data without the need for human-labeled data. This is important because labeled data can be expensive and time-consuming to collect.

Another advantage of using graphs for NLP is that they can be used to model multimodal data. For example, graphs can be used to represent the relationships between words, images, and documents. This is useful for NLP tasks that require reasoning over multiple modalities of data, such as image captioning and visual question answering.

Graphs are a promising new direction for NLP research. They offer a number of advantages over traditional NLP approaches, such as the ability to learn unsupervisedly, model multimodal data, and capture the temporal relationships between words and sentences. As research in graph learning continues, we can expect to see even more innovative and effective applications of graphs for NLP.

What is Deep Graph Learning?

Deep graph learning is a machine learning approach designed to model and extract knowledge from data organized in graph structures. Graphs, consisting of nodes and edges, prove particularly adept at representing data with complex relationships. For example, in NLP, a graph can represent the connections between words in a sentence, where each word corresponds to a node, and edges denote relationships between words.

Image source : https://www.linkedin.com/pulse/deep-learning-graphs-julio-bonis-sanz/
Jure Leskovec, Stanford University

Deep graph learning models facilitate the extraction of insights from graph-structured data. They can uncover intricate relationships, such as syntactic and semantic connections between words in a sentence or associations between different entities in a knowledge base.

One important milestone in the development of deep graph learning is the introduction of Graph Convolutional Networks (GCNs) in a 2017 paper titled “Semi-Supervised Classification with Graph Convolutional Networks” by Thomas Kipf and Max Welling. GCNs marked a significant advancement in deep graph learning, and they have since become a foundational model for working with graph-structured data.

Semi-Supervised Classification with Graph Convolutional Network by Thomas Kipf, M. Welling

Deep Graph Learning for NLP

Deep graph learning has demonstrated exceptional effectiveness in enhancing a variety of NLP tasks. Its strength lies in its ability to model intricate relationships between words and sentences, resulting in improved performance on NLP challenges. Here are some of the primary reasons why deep graph learning is instrumental in NLP:

1. Capturing Complex Relationships: Deep graph learning models can capture complex relationships between words and phrases in a sentence by learning to represent the sentence as a graph. In this graph, each word is represented by a node, and the relationships between words are represented by edges. Deep graph learning models can then learn to predict the properties of the graph, such as the edge types between nodes or the node attributes.

This ability to capture complex relationships is particularly beneficial for NLP tasks such as machine translation and question answering. For example, a machine translation model that can capture the complex relationships between words in a sentence can produce more accurate and fluent translations. Similarly, a question answering system that can capture the complex relationships between words in a question and the words in a passage of text can provide more informative and comprehensive answers.

2. Syntactic and Semantic Analysis: Deep graph learning models can provide detailed syntactic and semantic analysis of language by modeling graph structures. For example, a deep graph learning model can be used to identify the subject, verb, and object of a sentence, as well as the relationships between different clauses in a sentence. Deep graph learning models can also be used to identify the semantic roles of words in a sentence, such as agent, patient, and instrument.

This ability to provide detailed syntactic and semantic analysis of language is beneficial for a variety of NLP tasks. For example, a text classification model that can understand the syntactic and semantic structure of a text can be more accurate in classifying the text. Similarly, a sentiment analysis model that can understand the syntactic and semantic structure of a text can be more accurate in identifying the sentiment of the text.

State-of-the-Art Deep Graph Learning Models for NLP

Recent years have witnessed substantial advancements in deep graph learning models tailored for NLP. Several state-of-the-art models have achieved impressive results on various NLP tasks. Here are a few notable examples:

Graph Convolutional Networks (GCNs): GCNs represent a category of deep graph learning models adept at learning from graph-structured data. They have exhibited remarkable performance across NLP tasks such as machine translation, question answering, and text summarization.

Illustration of Graph Convolutional Networks (By Inneke Mayachita)

Graph Attention Networks (GATs): GATs, like GCNs, are deep graph learning models tailored for graph-structured data. However, they employ an attention mechanism to focus on the most pertinent nodes within a graph. GATs have demonstrated superior performance to GCNs in specific NLP tasks, such as machine translation.

Graph Attention Network Introduced by Veličković et al. in Graph Attention Networks

Graph Transformer Networks (GTNs): GTNs are a variant of the transformer architecture designed to handle graph-structured data. They have proven highly effective across various NLP applications, including machine translation, question answering, and text summarisation.

Source : Graph Transformer Networks by Seongjun Yun, Minbyul Jeong, Raehyun Kim, Jaewoo Kang, Hyunwoo J. Kim

In addition to the above models, there are a number of other state-of-the-art deep graph learning models for NLP, such as GraphSAGE, GIN, and Message Passing Neural Networks (MPNNs). These models have been shown to achieve impressive results on a variety of NLP tasks

Let’s delve into potential applications and some specific examples of how deep graph learning can enhance NLP applications:

  1. Machine Translation: Deep graph learning can be leveraged to develop machine translation models capable of capturing intricate word and sentence relationships, leading to more accurate and fluent translations. 👇🏼
  • Capturing long-range dependencies: DGL models can capture long-range dependencies between words and phrases in a sentence, which is essential for accurate machine translation. For example, a DGL model can learn the relationship between the subject and verb of a sentence, even if they are separated by several words.
  • Modeling contextual information: DGL models can model the contextual information of a sentence, which can help to improve the accuracy of machine translation. For example, a DGL model can learn that the word “bank” has different meanings in different contexts, such as “financial institution” and “riverbank.”
  • Translating between low-resource languages: DGL models can be used to train machine translation models for low-resource languages, which are languages that have limited amounts of training data available. This is because DGL models can learn to generalize from a small amount of data.

2. Question Answering: By enhancing the understanding of question semantics and context, deep graph learning can improve question-answering systems, rendering them more informative and effective. 👇🏼

  • Understanding question semantics: DGL models can be used to understand the semantics of questions, including the meaning of the words and the relationships between the different parts of the question. This can help to improve the accuracy of question answering systems.
  • Reasoning over knowledge graphs: DGL models can be used to reason over knowledge graphs, which are networks of interconnected entities and their relationships. This can help to improve the accuracy of question answering systems for complex questions that require knowledge of the world.
  • Generating informative answers: DGL models can be used to generate informative answers to questions, even if the answers require multiple sentences or require reasoning over multiple sources of information.

3. Text Summarisation: Deep graph learning can be harnessed to create text summarisation models with a refined ability to identify and extract essential information from lengthy texts. 👇🏼

  • Identifying important information: DGL models can be used to identify the important information in a text, even if the information is spread out over multiple sentences. This is because DGL models can learn the relationships between different parts of a text.
  • Generating concise summaries: DGL models can be used to generate concise summaries of texts, even if the texts are lengthy and complex. This is because DGL models can learn to identify the key information in a text and to generate summaries that are both informative and concise.
  • Summarizing multiple documents: DGL models can be used to summarize multiple documents at the same time, even if the documents are not related to each other. This is because DGL models can learn to identify the common themes and ideas across multiple documents.
Source : Freepik

In addition to the core NLP tasks of machine translation, question answering, and text summarization, deep graph learning has the potential to enhance various other NLP applications, including:

1. Natural Language Generation: Deep graph learning can empower the development of natural language generation models capable of producing more coherent and informative text. This could pave the way for advanced applications like chatbots and creative text generators.

2. Information Extraction: Deep graph learning can improve information extraction models, making them more accurate and efficient at extracting valuable information from textual data. This can be instrumental in applications like text mining and knowledge base construction.

3. Sentiment Analysis: Deep graph learning can refine sentiment analysis models, leading to more precise identification of sentiment in text. Such advancements can have implications for social media monitoring and customer service analytics.

Challenges

  • Training Data: need for large amounts of training data. This is because deep graph learning models need to learn the complex relationships between words and sentences in a language. However, there are a number of ways to address this challenge, such as using pre-trained models and transfer learning.
  • Computational cost: Training deep graph learning models can be computationally expensive, especially for large and complex datasets. This is because deep graph learning models need to learn to model the relationships between all of the nodes in a graph, which can be a computationally intensive process.
  • Robustness to noisy and outlier-laden data: Deep graph learning models can be sensitive to noisy and outlier-laden data. This is because deep graph learning models learn to model the relationships between all of the nodes in a graph, and even a single noisy or outlier node can disrupt the model.
  • Interpretability: Deep graph learning models can be difficult to interpret, which can make it difficult to understand why the model makes certain predictions. This can be a problem for NLP tasks where it is important to understand the model’s reasoning, such as for question answering systems.
Source : Freepik

Opportunities

  • Developing more efficient and scalable algorithms: Researchers are actively developing more efficient and scalable algorithms for training deep graph learning models. This could help to reduce the computational cost of training deep graph learning models for NLP tasks.
  • Designing more robust models: Researchers are also designing deep graph learning models that are more robust to noisy and outlier-laden data. This could help to improve the performance of deep graph learning models on real-world NLP tasks.
  • Developing new interpretation techniques: Researchers are developing new techniques for interpreting deep graph learning models. This could help to make deep graph learning models more transparent and explainable,which could be beneficial for NLP tasks where it is important to understand the model’s reasoning.
Source : Freepik

Overall, deep graph learning is a rapidly evolving field with a lot of potential for NLP. As the challenges of deep graph learning are addressed and new opportunities are explored, we can expect to see deep graph learning play an increasingly important role in the development of next-generation NLP applications.

I am excited to see how deep graph learning continues to transform the field of NLP in the years to come.

In Conclusion

Deep graph learning is a potent machine learning technique poised to reshape the landscape of NLP. Existing deep graph learning models have already achieved remarkable results in various NLP tasks, and the future promises even more substantial advancements.

As a budding NLP researcher, I am excited about the prospects of deep graph learning and its ability to model intricate language relationships within graphs. This capability opens doors to enhancing a broad spectrum of NLP applications. I look forward to contributing to the development of innovative deep graph learning models that will drive the next generation of NLP advancements.

Source : Freepik

Furthermore, the versatility of deep graph learning extends beyond enhancing existing NLP tasks. It holds the potential to pave the way for entirely new and groundbreaking applications that can enrich our interactions with computers and language. Deep graph learning’s ability to capture and comprehend complex relationships within language data is a powerful asset that will undoubtedly play a pivotal role in shaping the future of NLP.

One paper on Deep learning, graph-based text representation and classification: a survey, perspectives and challenges I found interesting is liked here — LINK

Feel free to contribute your thoughts, questions, and experiences in the comments section below. If you found this blog insightful, I’d greatly appreciate your support by considering a follow on Medium. Your engagement and feedback are invaluable!

LINKEDINWEBSITEDSC WEBSITEDATAX JOURNAL

--

--

DataX Journal
DataX Journal

Published in DataX Journal

This is the publication of the Data Science Community, a data science-based student-led innovation community at SRM IST. Here we publish blogs based on Data Analytics, Machine Learning, web and app development, current affairs in technology and more based on experience and work

ADITYA VERMA
ADITYA VERMA

Written by ADITYA VERMA

Exploring the world through words. 3rd-year student sharing insights on novel, movies, life, tech, travel, airsoft and more. Join the journey!