Study Guide: Concept 5 — The Protective Belt

Core Concept

Auxiliaries, instruments, initial conditions — the adjustable periphery takes every hit by design. Anomalies become routed work items. Adjustments must be content-increasing (predict new facts), not ad hoc (explain backwards only).

Key Terms

Protective belt · ad hoc (1/2/3) · content-increasing shift · blame routing

Case Summary

Neptune: belt adjustment predicting a findable planet — glory. Vulcan: same maneuver, predicting nothing findable, repeated — decay.

Application Checklist

• [ ] Map the belt around your core system (config, data, third parties, user models)
• [ ] Grade your last fix: predicted improvement or backward re-description?
• [ ] Find your Vulcan: the patch you've applied three times

Self-Test

1. How does the belt weaponize the Duhem problem?
2. Three grades of ad hoc-ness?
3. Neptune vs Vulcan — identical move, opposite verdicts. Why?