What is triangulation method?

Triangulation method is a concept in personal epistemology: When direct testing is impossible look for indirect evidence and converging indicators.

Example: You believe that your career stagnation stems from a fear of visible failure — a schema about your own psychology. You cannot test this directly the way you would test a factual claim, because the schema is about an internal state that resists controlled observation. But you can look for indirect evidence: Do you consistently choose safe projects over ambitious ones? Do you volunteer less when outcomes are publicly visible? Do you feel relief rather than disappointment when a stretch opportunity falls through? Does your journaling show a pattern of rationalizing conservative choices as pragmatic when they might be protective? No single indicator proves the schema. But when four or five independent signals all point the same direction, the convergence itself becomes the evidence. You cannot see the fear directly, the way astronomers cannot see dark matter directly. But you can observe its gravitational effects on everything around it.

This concept is part of Phase 15 (Schema Validation) in the How to Think curriculum, which builds the epistemic infrastructure for schema validation.