Was this feature available when the prediction had to be made?
Author a timestamped feature table. Remove future information and explain why shuffled test rows did not fix leakage.
A feature is eligible only if its availability time is no later than the prediction time.
Cut these cards apart. Use the original example first, then let a partner supply a changed case. Keep sealed/final cards with the teacher until the learner commits a rule.
Feature: Morning attendance
Available minute: 0
Prediction minute: 10
Value: 1
My prediction and reason:
Feature: Afternoon result
Available minute: 60
Prediction minute: 10
Value: 1
My prediction and reason:
Feature: Yesterday result
Available minute: -1440
Prediction minute: 10
Value: 0
My prediction and reason:
Timestamp eligibility alone does not establish consent, usefulness or absence of other leakage.