AI Anatomy Class · Part 0 · ChatGPT, who are you?

1. The next-word guessing game

Q. When you ask ChatGPT something, does it think up the whole answer at once?

1. Here's a sentence: "I walk to…" What word comes next?
2. There are lots of candidates: school, the, work… Even "pizza" could come next, strange as it sounds.
3. ChatGPT gives every candidate a number for how likely it is to come next. That number is a probability.
4. It picks the most likely word, "school", and puts it in the blank.
5. Then it starts over! It reads the longer sentence and predicts the next word again. This time, a period wins.
6. That's all ChatGPT does: guess the next word really well, and repeat.
7. But to guess well, you need knowledge, patterns and common sense. Where that ability comes from is the rest of our story.

Chapter summary

• ChatGPT calculates the probability of each word that could come next.
• It picks a likely word, adds it, and predicts again.
• Repeating just this step builds a long answer.