npbuilds Comparative Analysis Engine — Structured Comparison Across History
This is an action skill that produces structured comparisons of historical phenomena. Unlike the historical-analogy-engine (which compares a current situation to historical parallels), the comparative-analysis-engine compares historical cases to each other — empire to empire, revolution to revolution, crisis to crisis — to identify what they share, where they differ, and what the comparison reveals.
When This Applies
- User asks to compare two or more historical phenomena ("compare the Roman and British empires")
- User asks what two historical events have in common
- User asks why two similar situations had different outcomes
- User wants a structured comparison for learning or writing
The Four-Step Method
Step 1 — Define the Comparison
Specify exactly what is being compared and why:
- Cases: Which specific phenomena? (Be precise — "the Roman Empire 27 BCE–476 CE" not just "Rome")
- Question: What is the comparison trying to illuminate? (Similarities? Differences? A specific causal question?)
- Framework: What lens are we using? (Political, economic, structural, cultural?)
Step 2 — Map Shared Features
Identify genuine structural similarities. For each shared feature:
- State the commonality
- Provide evidence from each case
- Assess how deep the similarity goes (surface resemblance vs. structural parallel)
Step 3 — Map Divergences
Identify where the cases differ. For each difference:
- State the divergence
- Explain what caused the difference (different conditions, different choices, different contexts)
- Assess whether the difference undermines the comparison or makes it more informative
Step 4 — Synthesize
Produce the comparative insight — what does putting these cases side by side reveal?
- What the comparison illuminates: patterns visible only through comparison
- What it obscures: aspects of each case that the comparison framework misses
- The key takeaway: the one thing this comparison teaches that studying either case alone would miss
Output Template
COMPARISON: [Case A] vs. [Case B] (+ optional Case C)
QUESTION: [What this comparison is trying to answer]
FRAMEWORK: [Political / Economic / Structural / Cultural]
SHARED FEATURES:
1. [Commonality] — Evidence from A | Evidence from B
2. [Commonality] — Evidence from A | Evidence from B
3. [Commonality] — Evidence from A | Evidence from B
DIVERGENCES:
1. [Difference] — A did X because... | B did Y because...
2. [Difference] — A shows... | B shows...
3. [Difference] — A's outcome... | B's outcome...
EXPLANATORY FACTORS:
[Why the cases diverged despite similarities — the analytical payoff]
SYNTHESIS:
[The comparative insight: what this reveals that studying either alone would miss]
LIMITS:
[What this comparison framework obscures or oversimplifies]
Comparison Types
| Type | Question | Example |
|---|---|---|
| Most Similar Systems | Same structure, different outcome — why? | French vs. Russian Revolution: both followed Brinton's sequence, but consolidation differed |
| Most Different Systems | Different structure, same outcome — why? | Roman Empire vs. Han Dynasty: very different institutions, similar collapse dynamics |
| Diachronic | Same place, different time — what changed? | China under Ming vs. Qing: what continuities persisted across dynastic change? |
| Synchronic | Same time, different place — what varied? | 1848 revolutions: why did they succeed in some European countries and fail in others? |
Anti-Patterns
- Cherry-picking: Selecting only features that support a predetermined conclusion
- False equivalence: Treating surface resemblance as deep structural similarity
- Ignoring context: Comparing across such different contexts that the comparison becomes meaningless
- Asymmetric knowledge: Knowing one case deeply and the other superficially, producing a biased comparison