Question: Explain why Andrew Ng emphasizes looking for 'clues' in machine learning problems, and describe how examining a basic system contributes to this process.

Sample answer: Andrew Ng emphasizes looking for clues because they indicate which ideas are worth trying and which are not. Learning to read these clues can save developers months or years of wasted effort. Examining a basic system, even a flawed one, is crucial because it is through this examination that a developer can quickly uncover these clues, revealing the most promising directions for future development.

Key points:

• Clues tell you what is useful and not useful to try.
• Reading clues saves months or years of time.
• Examining a basic system reveals clues about promising directions.

Rubric: The essay must explain the primary benefit of finding clues (saving development time) and how a basic system helps uncover them (showing promising directions).