Evaluation and Overfitting

Lesson goals

• Metrics aligned with error cost
• Comparing training and test results
• Improving generalization

Core idea

How to tell genuine learning from memorizing training examples.

1. Metrics aligned with error cost: understand it in context, identify inputs and outputs, and define how the result will be verified.

2. Comparing training and test results: understand it in context, identify inputs and outputs, and define how the result will be verified.

3. Improving generalization: understand it in context, identify inputs and outputs, and define how the result will be verified.

Practical example

Consider a real application of “Evaluation and Overfitting.” Start small, identify available data, and compare the system with a clear baseline before expanding it.

Check your understanding

1. Explain “Evaluation and Overfitting” in your own words.
2. Give one appropriate and one misleading application.
3. What risk or limitation should be monitored?