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Unveiling the Mystery: Large Language Models (LLMs)

By Danish Hasarat posted Fri March 29, 2024 02:25 PM


Have you ever had a conversation with a chatbot that made you feel like you were talking to a real person? Or perhaps you’ve been impressed with a search engine’s ability to anticipate your next query before you’ve even typed it into the search box?

These are just a handful of examples of the power Large Language Models (LLMs) possess. But what are they? And how do LLMs work on language?

In this article, we’re going to dive deep into the world of Artificial Intelligence (AI), Machine Learning, and the secrets behind LLMs.

Introduction to Machine Learning (ML):

Let’s say you’re trying to teach a computer how to identify cats in images. Instead of providing it with a set of rules such as “cats have pointed ears” or “cats have whiskies”, you’re presenting it with hundreds or even thousands of images of cats and other animals.

The machine learns from the patterns in the images and comes up with its own set of rules for distinguishing cats from non-cats based on what it sees.

This kind of automatic learning is what we call machine learning. It learns from data and improves over time without having to be explicitly programmed.

To give you an idea of how machine learning works, imagine that you’re teaching a child how to recognize different animal species. You’ve shown them pictures of a cat, a dog, a bird, etc., pointing out each animal’s unique characteristics.

Gradually, they’ll start to recognize those patterns, and eventually they’ll be able to recognize a new animal that they’ve never seen before based on its similarities. Machine learning does the same thing, but with much more data and sophisticated algorithms at the core.

Machine learning can be divided into three main types:

  1. Supervised Learning: Under supervised learning, an algorithm learns to pair inputs with outputs by learning from a labeled dataset. For instance, each image in the dataset is labeled as “cat” and each image as “other things”. So, the algorithm learns to pair the correct inputs with the correct outputs.
  2. Unsupervised Learning: Unsupervised learning, on the other hand, is when an algorithm is given a set of data without being explicitly told what to do with that data. Instead, it has to find patterns and structure within the data itself. For instance, it might find that certain categories of images tend to have cats in them, even though it wasn’t explicitly told what a cat was.
  3. Reinforcement Learning: In reinforcement learning, an algorithm learns by reacting to an environment and getting rewarded or penalized for doing so. It learns to perform actions that increase the total reward over time. Reinforcement learning is commonly used in tasks such as game playing and robotics.

Introduction to Artificial Intelligence (AI):

Artificial intelligence (AI) is a broad term that includes machine learning and other techniques for creating machines that can do things that humans would need to be able to do. For example, they can understand natural language, identify objects in pictures, make decisions, and even write stories or compose music.

The purpose of AI is to build systems that can sense their environment, think about it, and act accordingly to accomplish a particular goal. While humans possess a general intelligence that enables us to perform a wide variety of tasks, most of today’s AI systems are specialized, which means they’re optimized for one particular task or a specific set of tasks.

  • Spot patterns: In the same way that you can see shapes in the sky or recognize people in a crowd by looking at their faces, AI systems are able to look at data and discover hidden patterns and relationships. For instance, an AI can look at historical sales data and predict future trends.
  • Make choices: Based on the data they learn, AI systems are able to make decisions. For example, imagine a self-driving vehicle that uses traffic data and sensor readings to determine when to apply the brakes or switch lanes.
  • Learn and improve: Do not underestimate these machines. As they are exposed to more information and experience, AI systems are constantly learning and improving. Think of it as learning to ride a bicycle. The more you practise, the better you get.

Introduction to Deep Learning (DL):

Deep learning is a branch of machine learning that draws inspiration from the structure and functioning of the brain. Artificial neural networks (ANNs) are at the heart of deep learning.

Neural networks are made up of connected nodes (similar to neurons in the human brain) arranged into layers. Neural networks can learn to identify patterns from data (e.g., images, text, sound) by changing the connections between nodes.

The key to what makes deep learning “deep” is the fact that there are many layers of nodes. As the network moves through the layers, it learns more and more abstract data representations. Each layer takes a feature from the input, and the deeper layers build on the representations learned from the previous layers.

Deep learning has found great success in a wide range of areas, such as Computer Vision, Natural Language Processing, Speech Recognition, and many more.

Deep learning’s ability to learn from hierarchical data structures has led to advances in image recognition, object recognition, translation of languages, and even complex games such as Go.

Introduction to Deep Neural Networks (DNN):

DNNs are the foundation of Deep Learning. DNNs are made up of several layers of connected nodes. Each layer performs a particular transformation on the data it receives.

The initial layer takes the raw data (for example, pixels from an image, or words from a sentence) and gradually converts it into higher level representations.

Nodes in a neural network are organized into layers, typically including:

  1. Input Layer: This layer takes in the raw data, like pixels in an image or words in a sentence.
  2. Hidden Layers: These are the layers between the input layer and the output layer. Each hidden layer takes the data and transforms it into higher-level elements.
  3. Output Layer: This layer outputs the final network output, such as an image classification label or a forecasted sentence.

During the training phase, the network makes changes to the synaptic weights (the connections between nodes) to reduce the difference between predicted output and actual output.

Stochastic gradient descent (SDS) and back propagation (back propagation) are optimization algorithms that carry the error gradient back through the network and update the weights.

Deep neural networks can solve complex problems across a wide range of domains, from image recognition to speech recognition and natural language understanding (NLU). Their ability to learn hierarchical representations (HDRs) of data is what makes them so powerful.

Introduction to Language Models (LM) and Large Language Models (LLMs):

A language model is an artificial intelligence (AI) model that is trained to learn and create human language. A language model learns the statistical structures of language from large amounts of text data and then generates new text that is similar to the text on which it was trained.

Linguistic models have traditionally been based on statistical techniques and are not capable of recognizing complex linguistic structures. However, recent developments in deep learning have enabled the creation of large language models or LLMs, which use deep neural networks to perform high-performance natural language processing (NLP) tasks.

Language learning machines (LLMs) are trained on large volumes of text, including books, articles and web pages. LLMs are trained using unsupervised and self supervised learning methods. LLMs learn to anticipate the following word in a text series based on the previous words. MLMs capture the syntactical and semantic content of language.

Learning from large volumes of text data, LLMs gain a deep knowledge of language and can create human-readable text that is well-structured, contextually pertinent, and grammatically accurate. LLMs are used in various areas, such as chatbots, VMs, content creation, sentiment analytics, and more.

How LLMs work?

In the world of AI, few innovations have captivated the imagination and revolutionized the natural language processing landscape quite like Large Language Model (LLMs). Driven by the latest advances in deep learning, LLMs have revolutionized the way we understand, generate, and interact with human speech. But how do LLMs work, and what is the magic behind their training? Let’s demystify how LLMs work.

Understanding the Architecture:

At the core of each LLM is a deep-learning architecture called the transformer. Initially introduced in a groundbreaking paper Attention is All You Need by Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Lukasz Kaiser, Illia Polosukhin, 2017), the transformer architecture changed the way we think about natural language processing. Thanks to the transformer’s attention mechanism, models are able to capture far-reaching dependencies and contextually relevant information more efficiently than ever before.

At the core, the transformer is made up of many sub-layers. Each sub-layer has its own self-processing mechanisms and feeds into the feedforward neural network. Sub-layers process the input data in sequence, turning it into higher-level representations that capture local and global context. By stacking layers of sub-layers, LLMs are able to learn more abstract and nuanced language representations.

Training the Behemoth:

An LLM’s journey starts with data — a massive amount of data. These models are avid readers of text data from various sources, including books, articles, web pages, and social media. This massive amount of text serves as a training ground for the LLM to master the complexities of language.

But what does the machine learning model do with this data? This is where the miracle of self supervised learning comes into play. Self supervised learning is one of the driving forces behind the rapid growth of machine learning. In self supervised learning, a model is given a task that does not need to be labeled. Instead, the model learns to anticipate missing or masked signals within a series of text.

For example, let’s say the model is asked to predict the next word after the previous words in a sentence, even though some of those words are masked. This is called masked language modeling. The LLM will need to learn a lot about syntax, semantics and context to make these predictions.

During the training phase, the LLM modifies its parameters-millions or even billions of them - using optimization techniques like stochastic gradients. Gradient updates fine-tune the model’s internal representations to reduce the difference between the model’s predictions and the data.

Here’s a breakdown of the training process:

  1. Data Preprocessing: Cleans and formats the raw data. For example, it may remove irrelevant information or standardize punctuation.
  2. Word Embeddings: Words are transformed into numbers. This enables the LLM to comprehend the relationship between words and concepts.
  3. Neural Network Magic: The LLM is composed of many layers of neural networks, often referred to as transformers. These transformers process the word sequences to find patterns and relationships.
  4. Backpropagation: The LLM shows examples of text and its expected output (for example, translation or completion). The LLM compares its own attempts to get the right result and makes changes to its internal connections to make it more accurate. This process is done millions of times.

The Power of Pre-training and Fine-tuning:

One of the driving forces behind the success of multilayered machine learning models (LLMs) is the idea of “pre-training” followed by “fine-tuning”. In a pre-training LLM, the model is trained on an extensive, heterogeneous text set using self-directed learning methods. This initial training enables the model to gain a general understanding of language structures and patterns.

After pre-training, a model can be trained with labeled data on particular tasks or domains. The fine-tuning process involves fine-tuning the model’s parameters to focus on a specific task or domain. For example, a model can focus on sentiment analysis or question answering, while another model can focus on language translation.

This transfer learning approach greatly reduces the training volume of labeled data, which makes LLMs faster and more flexible across different tasks.

Once trained, LLMs can generate text by predicting the next word in a sequence. Here’s a simplified view:

[Input] --> [LLM Analysis] --> [Prediction Time] --> [Building the Output]
  1. You provide an input: This could be a sentence, a question, or even just a single word.
  2. The LLM analyzes the input: It considers the word embeddings and the context of the surrounding words.
  3. Prediction Time: The LLM uses its knowledge to predict the most likely word to follow the input.
  4. Building the Output: The predicted word becomes the new input, and the process repeats, generating a sequence of words that hopefully forms coherent text.

Breaking Down Barriers:

LLMs have rewritten the rules of natural language processing (NLP), allowing machines to understand, create, and interact with human speech with unprecedented precision and proficiency.

From conversational agents, language translation, content generation tools, and more, LLMs power a new generation of AI-powered applications that are shaking up the way we interact with technology.

However, their vast potentials also raise ethical questions and issues, such as bias, equity, privacy, and abuse. As we use LLMs to open up new opportunities, it is important to tread carefully and use these technologies in a responsible and ethical way.

Challenges and Considerations

Training LLMs is no small feat. Here are some factors to consider:

  • Computational Power: Training also requires a lot of computing power, which is costly and consumes a lot of energy.
  • Data Bias: For example, if the training data is heterogeneous, then the LLM will continue to repeat these heterogeneous biases. Therefore, careful data selection is essential.
  • Explainability: One of the biggest challenges is that it’s hard to get a clear picture of how LLMs produce results. More research needs to be done to make LLMs more transparent.


To sum up, Large Language Models (LLMs) are at the cutting edge of artificial intelligence, challenging the limits of what machines can do in terms of understanding and creating human language.

By understanding the architecture and training process of LLMs, we gain a better understanding of the creativity and innovation that drives this transformative technology.

As we enter the thrilling world of LLMs, allow us to take advantage of the opportunities they offer while remaining mindful stewards of their influence on society.