Question: Explain how error analysis by parts can help decide whether a traffic-sign pipeline should focus more engineering effort on the sign locator or on the sign-type classifier.

Sample answer: In a two-stage pipeline, a wrong final prediction can come from either the first stage or the second stage. The sign locator may fail to find or crop the sign correctly, or the sign-type classifier may assign the wrong category after receiving a correct crop. Error analysis by parts means reviewing individual failures and assigning each one to the stage that caused it. For each mistaken output, you check whether the sign was located properly and, if it was, whether the classifier still made the wrong decision. After counting how many errors come from each stage, the team can see which component is responsible for more mistakes and put more effort into that part.

Key points:

• The pipeline has two distinct stages: sign locator and sign-type classifier
• A final error can originate in either stage
• Error analysis by parts traces each failure to its source component
• Counting errors by component shows where improvement effort should go
• The goal is to avoid spending time improving the less important stage

Rubric: Full credit explains that the pipeline has two possible error sources, shows how individual mistakes are traced back to the locator or classifier, and uses that count to decide where engineering effort should be concentrated.