Decline detection and light intervention policy

DEC-0014 - Decline detection and light intervention policy

Context

Need a practical rule to detect performance decline and react without making self-study flow too strict.

Decision

Decline detection uses OR logic:

• Signal A: learner has 2 consecutive mock tests with score drop.
• Signal B: learner average score in latest 7 days drops >=10% versus previous 7-day window.
• If any one signal is triggered, system marks learner as “dang tut phong do”.

Intervention action (self-study):

• System recommends a “3-bai cuu nhip” pack in this order:
  • easy warm-up,
  • medium stabilization,
  • weakness-targeted practice.

Intervention intensity:

• Light-touch only.
• System recommends and encourages but does not force.
• No blocking gate before learner continues normal flow.

Rationale

Combining both signals increases coverage (users with mock data and users without frequent mock tests). Light-touch intervention keeps user comfort and matches current product direction (not overly strict).