Post-Training Process
This section delves into the post-training phase of AI model development, highlighting how it refines model behavior and tailors it to specific applications. This is a crucial step in shaping the capabilities of AI systems and making them more user-friendly.
Refining Model Behavior
Post-training involves fine-tuning the model's behavior through a process known as reinforcement learning from human feedback (RLHF). This method leverages human input to guide the model toward producing outputs that are aligned with specific goals or preferences.
Here's a breakdown of the key aspects involved:
- Human Feedback: Human feedback is essential in guiding the model. This feedback can take the form of explicit ratings or rankings, where humans evaluate the model's responses.
- Reward Model: A reward model is trained to predict human preferences based on the provided feedback. This model serves as a guide for the reinforcement learning process.
- Reinforcement Learning: The model interacts with the environment (the task or application) and receives rewards based on its actions. The reward model acts as the feedback mechanism, indicating the quality of the model's responses.
- Iterative Process: RLHF is an iterative process, where the model is repeatedly fine-tuned based on human feedback and the reward model.
Targeting Specific Personas
Post-training helps mold the model to behave like a specific persona, catering to particular use cases. For example, Chat GPT is trained to be helpful and informative, whereas other models might be designed for entertainment or creative writing.
Examples:
- John Shulman: "In pre training, you're basically training to imitate all of the content on the Internet... You get a model that can basically generate content that looks like random web pages from the Internet. And then when we do post training, we're usually targeting a narrower range of behavior, where we basically want the model to behave like this kind of chat assistant..."
- Dwarkesh: "If there's no other model next, next year or something, you got AGI. What's the plan?"