Lens – Learn How AI Works

Lens is a short course in how AI works, made of 27 hands-on lessons you can finish in a few minutes each. Drag a temperature dial and watch the odds of the next word change. Push a fact out of a model's context window. Grade answers like an evaluator, catch a leaked test question, and decide which tool an AI agent should reach for. Train a robot that learns the wrong goal, trace a thought through a model step by step, and audit an AI for a hidden goal. Five units: • How a chatbot thinks: tokens, next-token prediction, temperature, embeddings, attention, and one pass through a transformer • How it learned: the stages of training, and how bias in the data shows up in what it says • Using it well: context windows, hallucinations and sources, prompting, spotting mistakes, tools and agents, and privacy • Where AI is heading: scaling trends, interpretability, alignment, evaluations, and AI and society • Can we trust it? Goals learned by mistake, hidden behaviour, reading a model's reasoning, superposition, tracing a thought, AI debate, and an alignment audit Each lesson has three missions. Finish them to earn XP and keep a daily streak. Four games in Practice: be the model and get scored the way it is in training, predict how temperature reshapes the chances of each next word, sort true answers from made-up and out-of-date ones in example chats, and race a boat for points, then see what a player that only wants points does with the same rules. The examples are written in advance, so every lesson works offline and nothing you type leaves your iPhone. No account needed: signing in with Apple or Google is optional, and your progress stays on your iPhone either way.