discovery that changed how I think about AI evaluation — and led me to build an open-source testing framework. ───────────────────────────────────────── Introduction I was proud of my AI tutor called ARIA. Every metric looked excellent: deepeval faithfulness: 0.94 RAGAS context precision: 0.89 Automated test pass rate: 94% I thought ARIA was ready. I was wrong. When real students started using it, the Socratic compliance rate was 22.2%. Same system. Same day. Two com...