Now, before we get into the details of how this works, let me explain what RLHF is. Basically, it’s a fancy way to fine-tune language models using human feedback. So instead of just training them on some random data like usual, you can actually ask people for their input and use that to improve the model’s performance.
But how do we get this human feedback? Well, we use a dataset called Stack Exchange (which is basically a bunch of questions and answers from those nerdy coding forums). And here’s where things get really cool: instead of just using the text data itself, we also include some extra information about which answer was chosen as the best one by other users. This allows us to train our model specifically on answering questions in a way that is similar to how people actually use Stack Exchange!
So now you might be wondering: what exactly does this RLHF process involve? Well, it’s basically a combination of three different techniques: Supervised Fine-tuning (SFT), Reward / preference modeling (RM), and Reinforcement Learning from Human Feedback (RLHF).
First up is SFT. This involves using some pre-trained language model as a starting point, and then fine-tuning it on our Stack Exchange dataset to improve its performance specifically for answering questions in this context. We use the LLaMA models developed by Meta AI for this purpose because they’re really good at handling large amounts of text data!
Next up is RM. This involves creating a reward function that measures how well our model is doing at answering questions based on human feedback. So basically, we give it some points if the answer it generates matches what other users have chosen as the best one, and deduct points if it doesn’t match. We then use this reward function to train our model using a technique called policy gradient reinforcement learning!
Finally, we get to RLHF itself. This involves collecting human feedback in real-time while the model is generating responses, and then using that feedback to improve its performance over time. So basically, as people use StackLLaMA to answer questions on Stack Exchange, they can provide feedback by clicking a button or typing some text. We then use this feedback to adjust our reward function and fine-tune our model even further!
And there you have it: the magic behind StackLLaMA! It’s basically a fancy language model that uses human feedback to improve its performance at answering questions on Stack Exchange, using a combination of Supervised Fine-Tuning (SFT), Reward / preference modeling (RM), and Reinforcement Learning from Human Feedback (RLHF). Pretty cool stuff, huh?