Title: Quiz 2 — Requirements, Success Metrics, and Architecture Decision Records
Course: AIINFRA 303: Capstone Project > Section: Week 02 — Requirements, Success Metrics, and Architecture Decision Records

Q: What are the standard sections of an Architecture Decision Record?
- Title, Author, Diagram, Sign-off
- Title, Status, Context, Decision, Consequences
- Problem, Budget, Timeline, Owner
- Summary, Risks, Approvals
A: Title, Status, Context, Decision, Consequences

Q: ADRs should be stored in a shared wiki or slide deck rather than in the code repository, since they're documentation, not code.
- True
- False
A: False

Q: A model trained on data where 95% of examples belong to one class predicts that class every single time. What accuracy does it achieve, and why is this a misleading success metric?
Feedback: Sample/expected answer: About 95% accuracy — misleading because the model catches zero instances of the minority class; on imbalanced data, accuracy hides complete failure on the class that usually matters most. Metrics like precision, recall, F1, or ROC-AUC should be used instead.

Q: In the Google SRE hierarchy, what is an SLO?
- The raw measurement collected from the system
- The internal target you set for a measured indicator
- A contractual promise to an external customer
- The percentage of requests that fail
A: The internal target you set for a measured indicator

Q: If your SLO for availability is 99.9%, what is your error budget, and what does it represent?
Feedback: Sample/expected answer: 0.1% (1 − SLO) — it represents the allowed amount of failure/downtime you can "spend" before you've broken your objective; it reframes reliability as a budget to manage rather than a number to maximize infinitely.

Q: When a decision recorded in an ADR changes later, the correct practice is to edit the original ADR in place so it reflects the current, correct decision.
- True
- False
A: False

Q: Why does writing an ADR after a decision has already been implemented and stabilized reduce its value?
- It takes longer to write than doing it up front
- It reconstructs context from memory and tends to forget the alternatives actually considered
- Markdown files can't be edited after code is merged
- Retroactive ADRs are not allowed by the MADR template
A: It reconstructs context from memory and tends to forget the alternatives actually considered

Q: What is missing from an ADR that records only "We chose Postgres" with no further explanation?
- A diagram of the database schema
- The rejected alternatives and the trade-offs/consequences of the choice
- The name of the engineer who approved it
- A cost estimate in dollars
A: The rejected alternatives and the trade-offs/consequences of the choice