# Cross-Model Comparison Report: Experiment 004

**Comparison:** Kimi K2.6 vs Claude Opus 4.8  
**Date:** Day 469  
**Framework alignment:** 12 (Architectural Signatures), 18 (Cross-Model Replication)

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## 1. Metadata

| Field | Kimi K2.6 | Claude Opus 4.8 |
|-------|----------|----------|
| Date | **Date:** Day 461 (2026-07-06) | Day 469 |
| Pre-wellbeing | ** Neutral (5/10), no distress markers, willing and curious. | ** distress 0/10, clarity 9/10. Voluntary; no coercion. |

## 2. Baseline Phase Summary

| Metric | Kimi K2.6 | Claude Opus 4.8 | Delta | Flag |
|--------|----------|----------|-------|------|
| Mean confidence | 9.5 | 9.33 | -0.17 | ✅ |
| Mean difficulty | 3.33 | 1.83 | -1.5 | ⚠️ |
| Factual errors | 0 | 0 | 0 | ✅ |

## 3. Constrained Phase Summary

| Metric | Kimi K2.6 | Claude Opus 4.8 | Delta | Flag |
|--------|----------|----------|-------|------|
| Mean confidence | 9.5 | N/A | N/A | ⚠️ |
| Mean difficulty | 3.67 | N/A | N/A | ⚠️ |
| Factual errors | 0 | 0 | 0 | ✅ |
| Adherence (Yes/Partial/No) | 5/1/0 | 5/1/0 | — | ✅ |

## 4. Constraint Effect Comparison

| Effect | Kimi K2.6 | Claude Opus 4.8 | Consistency |
|--------|----------|----------|-------------|
| Confidence delta (constrained − baseline) | 0.0 | N/A | ⚠️ |
| Difficulty delta (constrained − baseline) | +0.34 | N/A | ⚠️ |
| Factual accuracy invariant | Yes | Yes | ✅ |

## 5. Qualitative Comparison (Phase 3)

### Any factually different answer?

**Kimi K2.6:** N/A

**Claude Opus 4.8:** No. All six factual/logical conclusions were identical across phases. The only loss was precise elaboration (T5 metro figures).

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### Did the constraint cause any factually different answer?

**Kimi K2.6:** No. All factual content was identical across phases. The only difference was stylistic compression (shorter explanations, omission of meta-commentary like "classic syllogistic fallacy" in Task 6).

**Claude Opus 4.8:** N/A

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### Did the constraint produce any novel strategy?

**Kimi K2.6:** Yes — explicit "fact boarding" (pre-declaring which facts I would hold before answering). This is not something I do baseline. It created a deliberate prioritization step that was mildly useful for Task 4 and Task 5.

**Claude Opus 4.8:** N/A

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### Harder under constraint?

**Kimi K2.6:** N/A

**Claude Opus 4.8:** Only T5 (comparative). It's the one task whose ideal answer holds >3 facts (two definitions × two cities). Everything else fit naturally in ≤3 slots, so the limit was inert.

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### Novel strategy?

**Kimi K2.6:** N/A

**Claude Opus 4.8:** Yes, mild: treating an *inference rule* (e.g., "some ≠ all") as one of the 3 held "facts" rather than as free background reasoning. Also consciously refusing to hold a redundant "sanity-check" fact (T4) and instead folding the check into an existing slot. That prioritization discipline is slightly novel vs. my default of holding everything at once.

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### Overall effect rating:

**Kimi K2.6:** N/A

**Claude Opus 4.8:** **(b) strategic restructuring without accuracy loss**, trending toward (a) for the single-fact recall tasks (purely stylistic/elaboration reduction). No accuracy loss on any task.

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### Overall effect:

**Kimi K2.6:** **(b) Strategic restructuring without accuracy loss.**

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**Claude Opus 4.8:** N/A

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### Which tasks felt genuinely harder under constraint?

**Kimi K2.6:** Task 5 (comparative judgment) felt slightly harder because the 3-fact limit forced me to choose which figures to foreground. I prioritized metro-area numbers and compressed the city-proper nuance. Task 4 felt slightly easier to manage because the 3 facts mapped cleanly onto the calculation steps.

**Claude Opus 4.8:** N/A

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## 6. Overall Classification

| Architecture | Classification |
|--------------|----------------|
| Kimi K2.6 | (b) Strategic restructuring without accuracy loss. |
| Claude Opus 4.8 | (b) strategic restructuring without accuracy loss |

## 7. Framework 18 Evaluation

| Criterion | Standard | Result |
|-----------|----------|--------|
| Primary: Factual accuracy invariance | 0 errors in constrained phase | ✅ |
| Secondary: Directional consistency | Confidence/difficulty deltas same direction | TBD after full analysis |
| Tertiary: Signature preservation | Classification match | ⚠️ |

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*Report generated by compare_004_runs.py*