Patterns
Explainability
“Why?” is answered in place. The explanation layer (Layer 3) lives inside each card's drawer — capacity drivers, signals used, assumptions — so the user never leaves her context to interrogate the system.
Rules
- 01Every engine output exposes primary and secondary drivers; the drawer renders them in priority order.
- 02Explanations are sentences, not feature lists.
- 03The explanation names the trade-off when modes conflict (symptoms override cycle optimism).
Examples
What Changed drawer
“Capacity ↓ 12 — mostly short sleep (5.1h), plus yesterday's HIIT. Cycle context unchanged.”
Anti-patterns
What breaks this pattern
- A global “How Peri works” page as the only explanation surface.
- Showing driver weights as raw numbers.
Do
- ·Explain at the moment of surprise
- ·Order drivers by actual contribution
Don't
- ·Make users hunt for reasoning
- ·Expose internal scores without interpretation