{"blocks": [{"key": "bf3e4d6e", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "eca54bd7", "text": "You have built a model that flags fake accounts; leadership wants evidence it works well in production.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "bdd510b4", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "a0e4c665", "text": "Which evaluation metrics would you choose to judge the fake-account classifier and why? Explain the trade-offs among precision, recall, F1, ROC-AUC, and business costs of false positives versus false negatives.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "c264bc26", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "788aee43", "text": "Discuss class imbalance, threshold tuning, and cost-based metric selection.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}