Title: Discussion
Course: Advanced Data Science: A Graduate Course > Section: Module 5: Rigorous model evaluation

Describe a real case, from work, a project, or the news, where a single headline metric masked a costly error, and analyze the mismatch between the metric that was optimized and the cost that actually mattered. Post your initial analysis by mid-week (Wednesday of week 10), then reply substantively to at least two peers, either challenging their diagnosis or proposing a metric that would have caught the problem. The instructor responds within each thread to extend the discussion and correct misconceptions.