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C004 — IPCC Two-Axis Confidence Model

Research: R0052 Run: 2026-03-31 Mode: claim

BLUF

The claim is almost certainly correct. The IPCC uses a two-axis confidence model with evidence quality (Limited/Medium/Robust) and source agreement (Low/Medium/High). This is directly confirmed by the IPCC's own guidance note for AR5 lead authors.

Probability / Answer

Rating: Almost certain (95-99%) Confidence: High Rationale: The IPCC guidance note — the primary source document — explicitly defines these two axes with the exact terminology stated in the claim.

Reasoning Chain

  1. The IPCC AR5 Guidance Note on Consistent Treatment of Uncertainties defines evidence quality using three terms: Limited, Medium, and Robust. [Source: SRC01, High, High]
  2. The same guidance note defines agreement using three terms: Low, Medium, and High. [Source: SRC01, High, High]
  3. These two dimensions combine in a matrix to produce five confidence levels: very low, low, medium, high, and very high. [Source: SRC01, High, High]
  4. Academic analyses of the IPCC framework confirm the two-axis structure. [Source: SRC02, High, High]
  5. JUDGMENT: The claim accurately describes the IPCC confidence framework with the correct terminology for both axes.

Hypotheses

H1: The claim is substantially correct

Status: Supported Evidence for: IPCC primary documentation confirms both axes with exact terminology. Evidence against: None.

H2: The claim is substantially incorrect

Status: Eliminated Evidence for: None. Evidence against: Primary source directly confirms.

H3: The claim is partially correct — axes exist but with different terminology

Status: Eliminated Evidence for: None. The terminology matches exactly. Evidence against: The IPCC guidance note uses exactly "Limited/Medium/Robust" for evidence and "Low/Medium/High" for agreement.

Evidence Summary

Source Description Reliability Relevance Key Finding
SRC01 IPCC AR5 Uncertainty Guidance Note High High Defines both axes with exact terminology
SRC02 Springer — Confidence levels survey High High Academic confirmation of two-axis framework

Collection Synthesis

Dimension Assessment
Evidence quality Robust — primary IPCC documentation
Source agreement High — unanimous
Source independence Independent — IPCC official + academic analysis
Outliers None

Gaps

Missing Evidence Impact on Assessment
None significant Primary source fully confirms the claim

Researcher Bias Check

Declared biases: The researcher's methodology incorporates the IPCC model. Influence assessment: Low risk — factual description of a published framework.

Revisit Triggers

Trigger Type Check
IPCC AR7 revises the confidence framework policy Check IPCC guidance notes for AR7
IPCC changes the terminology for evidence quality or agreement axes policy Monitor IPCC methodology publications