The map app that finds a way around traffic jams, the next video an app picks for you, and the chatbot that answers questions in whole paragraphs: all of these are artificial intelligence, or AI. In this lesson we open the box and look inside to see how it works, why scientists copied the idea from the nerve cells in our brains, why it is brilliant at some things yet gets others hilariously wrong, and how we can use it wisely and safely.
An ordinary computer program follows rules that people have written, line by line. A calculator, for example, always adds numbers using the same formula. AI is a program where nobody writes all the rules. Instead, it works out the rules for itself from a huge number of examples. Tap to see where AI is hiding in everyday things.
Imagine writing rules to tell a computer how cats differ from dogs. It is really hard, because there are big cats, small dogs, pointy ears and floppy ears. So scientists changed their approach: they give the machine lots of labelled examples and let it find the patterns itself. Have a go at being the teacher. Tap the board to add examples. The background colour shows what the machine would guess if it met a new animal in that spot.
Vertical axis: the higher up, the pointier and more upright the ears
In Lesson 8 we saw that a neuron receives signals from many neighbours. Some signals excite it and some calm it down. If they add up to something strong enough, it fires a signal onwards. Scientists copied this idea to make the artificial neuron, which is just a small equation: multiply each input by a weight, add them together, then check whether the total is over a threshold. Try setting the weights yourself.
This is what we call training an AI. We give it eight examples along with the right answers and let the machine guess. Every time it guesses wrong, it nudges the weights a little in the right direction, and it keeps going round until it gets them all right. Press one round at a time to watch the changes.
| Sunny | Homework done | Raining | Right answer | Machine’s guess |
|---|
| Human brain | Today’s AI | |
|---|---|---|
| Energy use | About 20 watts, like a small light bulb | Training uses as much electricity as thousands of homes use in a whole year |
| How many examples does it need? | A child can recognise a giraffe after seeing one just a few times | It needs to see thousands to millions of pictures |
| What is it good at? | Understanding feelings, adapting to new situations, and having a body to experience the real world | Reading huge amounts of information very fast, without getting tired or bored |
| Does it have feelings? | Yes: happiness, pain, fear | There’s no evidence it feels anything, even if it types that it’s happy |
Chatbots such as ChatGPT or Claude are trained to do one thing over and over: guess what the next word is likely to be. They have read more text than everyone on Earth could read in a lifetime, so they guess very well. Try playing with this tiny word-guesser that learned from just a handful of sentences.
The numbers are chances. The machine works them out by counting, in the sentences it has read, how often each word came after this one. Real chatbots don’t just look at the one word before. They can look back over pages of the conversation, but the idea is the same.
Because they are trained to put together words that sound likely. They weren’t built to open a book and check the facts every time. If we ask about something they don’t know, they may string together words that sound convincing but aren’t true, like inventing the title of a book that doesn’t exist. Researchers call this hallucination, which means seeing things that aren’t there.
Thai is written without spaces between words, so the machine first has to guess where each word begins and ends. For example, ‘takrom’ could be read as ‘ta klom’ (round eyes) or ‘tak lom’ (to sit out in the wind). There is also much less Thai text on the internet than English, so many AI models are less good at Thai. That’s why Thai researchers are building their own Thai-language AI too.
A camera doesn’t see a cat. It only sees millions of tiny dots, and each dot is a number that says how bright it is and what colour. AI learns which arrangements of numbers mean an edge, which mean an ear and which mean a cat’s face. Try drawing on the grid and see what the machine sees.
A single phone photo has about 12 million dots, and each dot has three numbers for red, green and blue. That adds up to tens of millions of numbers per picture.
Many image-making AIs start from a picture of messy random dots, like a TV screen with no signal, then gradually remove the mess step by step over dozens of rounds, guided by our instructions, until it becomes a picture that matches the description. Every illustration in this lesson was made this way, and a doctor checked each one before it was used.
AI doesn’t lie on purpose. It has no intentions at all. But it can be wrong in many ways, and it often answers in the same confident tone whether it’s right or wrong. Tap each one to find out.
AI is a tool, like a calculator or a library. Used the right way, it helps us learn faster. Used the wrong way, our brain gets no practice at all. Remember Lesson 12? The brain gets stronger by doing its own thinking.
An easy test: close the screen and try explaining it to someone at home. If you can’t, it means the AI understands it, but you don’t yet.
A short request gets a vague answer. A request that says who you are, what you want and in what form gets an answer you can actually use. Pick a task, then tick the ingredients one at a time and watch the prompt change.
For children and adults alike. Each idea comes with an example prompt you can type straight away.
Read the name of each thing and choose whether it learns from examples, follows rules people wrote, or doesn’t use a computer at all. You have 45 seconds.
Many hospitals have started using AI to help doctors, for example to look for bleeding in brain scans, to screen photos of the retina in people with diabetes, and to warn when blood test results look unusual. But the person who decides on treatment, explains it so the patient understands, and takes responsibility for the result is always the doctor.
Asking good questions, checking whether answers are right, understanding the feelings of the person in front of you, working as a team, and taking responsibility for what happens. You can practise these skills starting today, by reading, talking with real people, and making things with your own hands.
Maths helps you understand how machines learn, and programming lets you build things yourself. But just as important is knowing about the area where AI will be used. Good medical AI needs doctors to help design it, and farming AI needs people who understand rice and soil.
Every lesson in Body 101 was made by one doctor working with several advanced AI systems. Each one has a different job, like a team in a hospital. The doctor leads the team, sets the content and checks every piece before it goes online. Tap each step to see which AI it used, what the AI did and what a person checked.
While this series was being made, the AI really did make mistakes. The first heart picture had blood vessels joined to the wrong chambers. The cat-and-dog board in part 2 once guessed dog everywhere when there were only a few examples. The number boxes in several lessons were displayed badly without anyone noticing. Every one of these was caught because someone opened the real thing and pressed every button.
Researchers call this design human-in-the-loop: let AI do the fast, heavy work, but keep a person as the checker and decision-maker wherever mistakes are not allowed.
When you read news or articles about AI, you’ll often come across these words. They are split into three levels. Level 1 words are used every day, Level 2 words explain how AI learns, and Level 3 words are the ones AI developers use with each other. Start with Level 1, then work your way up.
Self-test mode uses the same idea as Lesson 12. Read the word, try to explain it in your head first, then tap the card to check. It works much better than just rereading.
Every question from this lesson is in the Body 101 arena. Race the clock, duel someone at home, play as a team, beat the bosses, or practise with no timer at all.