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Same Causal Effect, Different Bill: Derivation Graphs and the Estimand Trap

The formula is not a clerical detail A business asks a causal question: What happens if we change X? The analytics team returns a formula. Everyone relaxes. The effect is identifiable, the notation looks official, and a graph somewhere has probably been blessed by someone with a PhD. Excellent. Time to move to dashboards. ...

June 13, 2026 · 14 min · Zelina
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Confidence, Not Confidence Tricks: Statistical Guardrails for Generative AI

A product team launches an AI assistant. The demo works. The benchmark looks respectable. The model even says “I’m confident” with the serene authority of a consultant who has never owned a pager. Then the real users arrive. Some ask ambiguous questions. Some ask adversarial questions. Some ask perfectly normal questions that happen to sit outside the model’s competence. The assistant still answers. Sometimes it refuses too often. Sometimes it refuses too late. Sometimes its confidence score is less a forecast and more a decorative sticker. ...

September 13, 2025 · 14 min · Zelina