Choose Precision, Recall, or F1 for Agent Evaluation
Company: ByteDance
Role: Software Engineer
Category: Machine Learning
Difficulty: medium
Interview Round: Technical Screen
You need to evaluate three agents whose outputs have different levels of trustworthiness. For a particular task, each agent can make a positive decision, such as flagging an item as requiring action. Ground-truth labels can be obtained for a representative evaluation set.
How would you choose among precision, recall, and F1 when evaluating these agents? Explain how your choice changes when a false positive is more costly than a missed positive, when a missed positive is more costly, and when both error types matter. Do not assume that an agent's reputation determines which metric should be used for it.
### Constraints and Clarifying Questions
- Define the positive class and the action taken on a positive prediction before choosing a metric.
- Compare agents on the same task, labeling standard, and relevant case distribution.
- Clarify the cost of a false positive and a false negative, and whether outputs are reviewed by a person before action.
- State whether the agents expose confidence scores that support threshold selection or only final decisions.
```hint Start from a wrong decision
For the same item, consider the consequence of acting when no action was needed and the consequence of failing to act when it was needed. A single aggregate score can conceal either failure.
```
### What a Strong Answer Covers
- Definitions of precision, recall, and F1 using true positives, false positives, and false negatives.
- A metric choice tied to the consequences of each error type rather than a vague trust ranking.
- A fair comparison of the three agents, including thresholds when available and the underlying confusion counts.
- The limitations of F1 and of reporting a metric on a small or unrepresentative sample.
### Follow-up Questions
- How would you compare a cautious agent that rarely produces a positive decision with one that flags most items?
- What should you report when an agent predicts no positives or the evaluation set contains no actual positives?
- If an agent's positive decisions are automatically executed instead of reviewed by a person, how might your evaluation criterion change?
Overview: Choose precision, recall, or F1 to evaluate three agents by error costs, decision thresholds, and representative ground-truth evidence.