── ── Mental model
Three-Radius Model — 认知/能力/行动三半径
Three distinct circles govern performance: what you understand (cognition radius), what you can do (capability radius), and what you actually do (action radius). These are almost never the same size — the gaps between them are where most performance is lost.
How it works
Output artifact: Three-Radius Diagnostic. Gate rule: Each circle requires specific, observable evidence — not self-report.
Step 1 — Map cognition radius. List 3-5 things you understand well enough to evaluate others' work, explain mechanisms, predict outputs, and name your understanding boundary. Validation test: could you teach each item to a peer and receive useful critique? If not, it is in your awareness radius, not cognition radius. Gate 1: 3-5 items passing the validation test.
Step 2 — Map capability radius. List 3-5 things you can DO with demonstrated, externally evaluated performance. Understanding how something is done ≠ being able to do it. Gate 2: 3-5 items, each with a demonstrated output and external evaluator.
When to use it
- user says 'I know what to do but I'm not doing it', 'we understand the problem but can't fix it', 'effort isn't translating to results', 'why isn't our team executing?', or 'I feel stuck despite being competent'
- Also activate for pre-planning skill development or post-mortem gap analysis
When not to use it
When the decision is routine and reversible, applying a formal method costs more than it returns.
Worked example
Nikola Tesla's Three-Radius Divergence, 1880–1943
Nikola Tesla represents one of history's most documented cases of extreme divergence between the three circles — and its consequences.
Install this skill (free, MIT)
npx skills add deciqAI/knowledge-skills