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think-reference-class-forecastinglisted

Produces a reference-class estimate by defining a class of similar past cases, taking their base-rate distribution of outcomes, and anchoring the forecast on that outside view rather than the optimistic inside view, with a conservative adjustment for specifics. Use when forecasting cost, time, or odds of success for a project prone to optimism or the planning fallacy.
product-on-purpose/thinking-framework-skills · ★ 1 · AI & Automation · score 77
Install: claude install-skill product-on-purpose/thinking-framework-skills
<!-- thinking-framework-skills | https://github.com/product-on-purpose/thinking-framework-skills | Apache-2.0 --> # Reference Class Forecasting People forecast from the inside view, building an estimate from their own plan's details, which invites optimism and the planning fallacy. This skill replaces that with the outside view: find a reference class of similar past cases, take the base-rate distribution of how they actually turned out, and anchor the forecast on that, adjusting only cautiously for genuine specifics. The output is a **reference-class estimate**. The honest constraint: it requires real base-rate data; inventing a distribution is worse than admitting uncertainty. ## When to Use - Forecasting cost, time, or odds of success for something with comparable precedents. - The inside-view estimate is likely optimistic. - High-stakes commitments prone to the planning fallacy. ## When NOT to Use - Genuinely novel undertakings with no comparable reference class. - When you have no real base-rate data and would have to invent it. - When the specifics genuinely dominate and no class is comparable. - When a point certainty is expected (this produces a distribution). ## Instructions When asked to forecast with the outside view, follow these steps: 1. **State what is being forecast** (cost, duration, success odds) and the inside-view estimate if one exists. 2. **Define the reference class.** Identify the set of genuinely comparable past cases, and say why they are com