What changed inside

Something changed between Vincenza's bad guesses and her good ones. Whatever she learned was not a rule she could easily say out loud.

So look at what she actually did, step by step. It was the same four steps every time:

1. She tasted the wine.
2. She guessed a price.
3. She was told the correct price.
4. She saw how far off she was.

Then a new bottle arrived and she did those four steps again, throughout her practice.

Now ask a simpler question. Which step gave her new guidance?

The tasting gave her something to judge. The guess showed what her current judgement produced. The correct price supplied a target.

Step 4 joined them together: the distance between her guess and the correct price. Guess 200 dollars for a 35 dollar bottle and the feedback is specific. The guess was 165 dollars too high.

That distance has a name. It is called the error.

Using that difference to guide the next adjustment is called error correction. Guess, check the error, adjust a little, try again.

Those four steps do not prove exactly what changed in Vincenza's brain. They do give us a concrete learning loop to build and test.

Before deciding what the error can change, note that correction does not have to make every guess perfect. It only has to make the next guess less wrong.