Low Rank Adaptation: Reduce the Cost of Model Fine-Tuning

Low rank adaptation (LoRA) refers to a method for retraining an existing large language model (LLM) for high performance at specific tasks. By reducing the training parameters required to retrain a model, LoRA makes it faster and more memory-efficient to fine-tune LLMs. Low rank adaptation reduces the time and resources needed to train large language models for purposes like computer vision, natural language processing (NLP), and recommendation systems. 

Learn more about low rank adaptation and how it works, then explore careers where you can use LoRA to retrain large language models. 

What is low-rank adaptation?

Low rank adaptation is a faster and more efficient way of training large language models and other neural networks. The training process for a neural network is time-consuming and resource-heavy. You must fine-tune the model if you want to use a foundational model like Google Gemini or ChatGPT for a specific task. Instead of starting from scratch, you can use low-rank adaptation to lower the resources required to fine-tune a model, making it faster and more memory-efficient.

How does low rank adaptation work?

Low rank adaptation reduces the number of training parameters you need to fine-tune a model. To understand how this happens, explore the initial process of training a large language model. 

Training large language models

A large language model has layers of neural networks that process data like text or images to learn the patterns and defining characteristics of the training data set. After training with a vast amount of data, the model can generalize what it learned and apply that knowledge to other data sets. This is how a single large language model like ChatGPT or Claude AI can accomplish many different tasks, such as writing a poem, generating an image, or analyzing data. 

These foundational models can have billions or trillions of parameters that impact how they learn and process data. The sheer volume of learning parameters is what allows the large language model to handle so many different tasks. If you want the model to be highly specialized at a specific task, you need to fine-tune the model to get better performance. Fine-tuning such a massive LLM can be limiting since it requires time and money. Low rank adaptation is a strategy where you can avoid fine-tuning all of the parameters and focus solely on the parameters you need for your specific purpose. 

Low rank adaptation 

Low rank adaptation effectively stops the model from changing the internal parameters, like the weights between nodes that help the model qualify data and understand how data points relate to the whole. The weights within a neural network can change as needed during fine-tuning. By freezing them at their current values, the model will not need to undergo the time-consuming and computing power-heavy process of adjusting all of the internal parameters, and the model will continue to work as expected.

Next, you can add a low rank matrix, which adds a small set of weights that includes only those you need for the task onto the existing weights of the model. Low rank is a mathematical concept that means this data is less complex than the original data. (It has a lower rank.) It’s similar to adding a filter to a camera lens in that you’re not changing what’s there inside the model; instead, you’re overlaying additional data onto it. By training only those added weights, you can train your model for specialized tasks faster using fewer computational resources. 

Using low rank adaptation, you can take an open-source large language model and fine-tune it to your specific needs without training an entire LLM from scratch. 

Low rank adaptation examples

Low rank adaptation is applicable to any situation where you train a neural network to accomplish a task. You can use LoRA in projects like: 

• Natural language processing: Large language models are particularly well suited to natural language processing tasks because they can process and understand sequential data, like text. LoRA is a lightweight method of fine-tuning these models for specific tasks. For example, you could use LoRA to fine-tune a large language model to grade papers and homework in a classroom setting. The model would retain the overall knowledge of a foundational language model but specialize in the specific resources the students are learning from, such as a textbook. 

• Computer vision: You can also use low rank adaptation to train models that generate images or understand images. A real-world example of such a model is Stable Diffusion, a generative AI model you can prompt to create images in many different styles. Low rank adaptation could help you produce a lightweight model based on Stable Diffusion but specialized to a specific task, such as illustrating a book or creating a series of specific images. 

• Recommendation systems: You can use this popular method of analyzing a user’s behavior or sales history to recommend something else they might be interested in. You may be familiar with Netflix or Amazon’s recommendation systems, which take factors like your past use and how other users with similar interests behave to predict what you might want next. You can use low rank adaptation to train a recommendation system that personalizes to each user in a way that keeps that user's data separate from the overall system. 

Who uses low-rank adaptation?

Professionals who create and train large language models and other neural networks can use low rank adaptation for faster fine-tuning and lightweight, sharable models. If you want to explore a career where you can train large language models, consider careers like data scientist, machine learning engineer, or AI researcher. 

1. Data scientist

Average annual salary in the US (Glassdoor): $118,075 [1]

Job outlook (projected growth from 2023 to 2033): 36 percent [2]

As a data scientist, you will help companies and organizations understand and analyze data. Neural networks like large language models are useful for data scientists to find patterns within data, which means you may train models for specific tasks using LoRA. In this role, you will determine what data you need, collect, preprocess, and analyze the data, and then create visualizations or reports to present your findings to leadership or colleagues. 

2. Machine learning engineer

Average annual salary in the US (Glassdoor): $122,823 [3]

Job outlook (projected growth from 2023 to 2033): 36 percent [2]

As a machine learning engineer, you will use artificial intelligence and machine learning principles to create algorithms and models to solve complex problems. You might use low rank adaptation to train existing models for specialized uses in a wide variety of industries, including health care, manufacturing, entertainment, and transportation, working with robotics, self-driving vehicles, and more. 

3. AI researchers

Average annual salary in the US (Glassdoor): $99,352 [4]

Job outlook (projected growth from 2023 to 2033): 26 percent [5]

As an AI researcher, you will study artificial intelligence and find ways to advance the technology in the field. You might use low rank adaptation to create models specialized for practical purposes or to understand the theoretical principles of large language models. In this role, you will design and execute research experiments and share your work with project stakeholders and the greater scientific community. 

Learn more about machine learning with Coursera

Low rank adaptation is a strategy for fine-tuning a foundation neural network for a specific task without building a model from scratch or tackling the resource-heavy job of retraining the entire model. 

If you want to learn more about machine learning and artificial intelligence techniques like LoRA, you can find programs on Coursera to help you learn new skills or train for a job working with neural networks. Consider enrolling in the Deep Learning Specialization to learn more about working with neural networks. Alternatively, you could develop job-ready skills with the IBM Machine Learning Professional Certificate.