# Evaluate Model-Targeted Subscription Notifications
A classification model identifies users likely to subscribe, and the product team plans to send those users a notification. Design a measurement and experimentation plan. Include checks before the experiment, how to interpret a flat result, and alternatives to a conventional user-level A/B test with their trade-offs. Explain how the plan separates model prediction quality from the incremental effect of sending notifications.
### What a Strong Answer Covers
- Subscription and user-experience outcomes with a stable eligible-population denominator.
- A design estimating notification incrementality rather than only predictive discrimination.
- Instrumentation validation, A/A checks, allocation checks, and a prespecified analysis.
- A diagnosis of flat effects and at least two alternative evaluation designs with assumptions.
```hint A likely subscriber may subscribe anyway
High predicted conversion does not establish that the notification changes the user’s decision.
```
### Follow-up Questions
- How would you decide whether to target likely subscribers or users most persuadable by a notification?
- What evidence can an offline classifier evaluation provide before any notification is sent?
Overview: Evaluate subscription-targeting notifications with incrementality metrics, A/A preparation, flat-result diagnosis, and alternative causal designs.
A classification model identifies users likely to subscribe, and the product team plans to send those users a notification. Design a measurement and experimentation plan. Include checks before the experiment, how to interpret a flat result, and alternatives to a conventional user-level A/B test with their trade-offs. Explain how the plan separates model prediction quality from the incremental effect of sending notifications.
What a Strong Answer Covers Guidance
Subscription and user-experience outcomes with a stable eligible-population denominator.
A design estimating notification incrementality rather than only predictive discrimination.
Instrumentation validation, A/A checks, allocation checks, and a prespecified analysis.
A diagnosis of flat effects and at least two alternative evaluation designs with assumptions.
Follow-up Questions Guidance
How would you decide whether to target likely subscribers or users most persuadable by a notification?
What evidence can an offline classifier evaluation provide before any notification is sent?