Question: Explain how a team can use a manual review of roughly 100 mistakes made on a validation set to decide which problems deserve the most attention.

Sample answer: A team can look through about 100 validation errors and sort each one into a small number of categories, such as wrong labels, confusing inputs, or model failures on rare cases. After tallying how often each category appears, the team can estimate which types of mistakes account for the largest share of the total error. That makes it easier to choose the highest-value fixes first, instead of spreading effort evenly across all problems.

Key points:

• Review a sample of about 100 validation errors
• Group the mistakes into meaningful categories
• Count how often each category appears
• Focus engineering work on the categories that contribute most to the overall error

Rubric: A full-credit response must describe sampling about 100 validation mistakes, classifying them into categories, counting the categories, and using the counts to prioritize the most common or costly error types first.