Reinforcement learning, explained with a minimum of math and jargon

It’s Agent Week at Understanding AI! This week I’m going to publish a series of articles explaining the most important AI trend of 2025: agents! Today is a deep dive into reinforcement learning, the training technique that made agentic models like Claude 3.5 Sonnet and o3 possible. Today’s article is available for free, but some articles in the series—including tomorrow’s article on MCP and tool use—will be for paying subscribers only. I’m offering a 20 percent discount on annual subscriptions through the end of the week. That’s the best price I’ll offer for the rest of 2025. Please click here to subscribe. In April 2023, a few weeks after the launch of GPT-4, the Internet went wild for two new software projects with the audacious names BabyAGI and AutoGPT. “Over the past week, developers around the world have begun building ‘autonomous agents’ that work with large language models (LLMs) such as OpenAI’s GPT-4 to solve complex problems,” Mark Sullivan wrote for Fast Company. “Autonomou

It’s Agent Week at Understanding AI! This week I’m going to publish a series of articles explaining the most important AI trend of 2025: agents! Today is a deep dive into reinforcement learning, the training technique that made agentic models like Claude 3.5 Sonnet and o3 possible. Today’s article is available for free, but some articles in the series—including tomorrow’s article on MCP and tool use—will be for paying subscribers only. I’m offering a 20 percent discount on annual subscriptions through the end of the week. That’s the best price I’ll offer for the rest of 2025. Please click here