Rocket tries a shortcut. He trains a new model with only two tool photos: two hammers.
Then he shows it a ruler. The model has never seen a tool with no handle!
"What do you notice?" Raven asks. "It only knows hammers."
Nova blinks. "Here is a hint," she says. "How many kinds of tools are there?"
Machine learning needs a huge number of examples.
With only a few examples, a model can miss important patterns.
Rocket's two-photo model never saw a tool with no handle. So it could not learn that.
More examples, of many different kinds, help a model learn better patterns.
| Model | Training photos | Kinds of tool photos seen |
|---|---|---|
| Rocket's shortcut model | 2 | hammers only |
| The crew's model | 16 | tools with handles and tools without |
The labels in training data must be right.
Imagine someone labels a rock photo as plant by mistake.
Then the paper model might learn that lumpy things can be plants.
People check their labels carefully. Mistakes in the data teach wrong patterns.
| Statement | True or false? |
|---|---|
| Machine learning needs a huge number of examples. | ? |
| Two examples are plenty for any model. | ? |
| A wrong label can teach a wrong pattern. | ? |
| Examples of many different kinds help a model learn. | ? |
Excellent work! Tomorrow we review training data and the people behind it.