Instead of just tracking watch time, I'd include short in-video prompts, adaptive quizzes, and real-world application tasks that require explaining concepts in their own words. Discussion boards with peer teaching can also reveal depth of understanding. AI can analyze written or spoken responses for reasoning patterns, not just correctness. Tracking revision attempts shows learning progress, while scenario-based challenges expose shallow memorization. Engagement signals like pausing, rewinding, or skipping also hint at confusion points. Together, these signals create a fuller picture of mastery.