Triangulation (Source Triangulation)

What makes sources independent

Independence is the whole point. Two evidence items are commonly treated as independent only if:

1. neither states the claim on the basis of the other;
2. they do not share an origin (one press release, one filing, one interview, one dataset);
3. they are not copies, translations or syndications of one text; and
4. neither relies on a third source that the other also relies on for this claim.

Signs that items are not independent include identical wording or quotes, the same figures with the same rounding, publication in a short window after one announcement, and attribution to the same release. Where independence cannot be shown, the items count as one origin. The practical rule is to count origins, not documents: a subject's filing and the same subject's press release are one origin for facts only the subject knows, and confirming such a fact needs a different party, such as the counterparty or a regulator acting on its own findings.

Forms of triangulation

• Across sources: the same claim from origins with separate access to the fact.
• Across kinds of evidence: a document, a registry record and an observed event that bear on the same claim. The Berkeley Protocol calls support from outside an item external corroboration and checks it alongside the item's internal consistency (paras. 193-194).
• Across time: dates and times corroborated by independent indicators, which the Protocol calls chronolocation (para. 191).

Repeated captures of one source over time show that the source is consistent. They do not independently confirm the fact.

When sources disagree

A disagreement is checked in a fixed order before anyone decides which source is right:

1. Dates. Do the sources speak as of different dates? A changed role or a new fund size is a change, not a conflict. See temporal validity.
2. Definitions. Do they measure different things? Regulatory assets under management on Form ADV and a marketing AUM figure are different attributes.
3. Identity. Are they describing the same entity? Similar names often belong to distinct allocators. See entity resolution.
4. Error. Only then is one value treated as wrong, weighing each source's authority for the claim and its reliability.

Until the question is resolved, both values stay visible with their evidence, and the disagreement itself is recorded as a source conflict.

Limits

Triangulation raises support for a claim; it does not prove it. Independent-looking sources can share a hidden upstream source, and all of them can repeat the same stale figure. Agreement between two weak sources is not automatically stronger than one authoritative primary source: for an adviser's registration status, the regulator's record settles the question. Fixed thresholds such as "three sources" are conventions of particular methodologies, not part of the definition. US analytic standards (ICD 203) ask analysts to use all available relevant sources and to describe the quality of those sources, rather than to reach a count. Deciding how much each item counts (evidence weighting) is a separate step: triangulation first asks whether the items are independent at all.

How Altss applies this (Altss methodology)

In Altss's three-dimension evidence model, triangulation is corroboration and belongs only to the validation status of a claim, never to its evidence origin or its derivation status. A claim is CORROBORATED when it is supported by at least two evidence items whose chains do not share an origin (neither copied from the other nor from a common upstream source) and there is no unresolved contradiction; the independence basis is recorded. Validation statuses take precedence in the order CONFLICTING, RESEARCH_VALIDATED, CORROBORATED, UNVERIFIED, and every status carries the date it was assessed.

Corroboration and review are separate facts: a reviewer can confirm a claim against a single filing (RESEARCH_VALIDATED) without it being corroborated, and the count of independent evidence items is recorded separately. The independence tests and conflict order are set out in the Source Reliability & Confidence Methodology and the Evidence & Provenance Standard.

Not the same as

• Source Reliability: Reliability grades a source from its record. Triangulation tests a single claim against independent sources.
• Confidence Score: A confidence score summarises how strongly the evidence supports a claim; triangulation is one check that feeds it, by testing whether the supporting items are independent.
• Primary Source: A primary source is close to the fact; triangulation asks whether a second, independent source agrees. One authoritative primary source can settle what several derivative copies cannot.

Common mistakes

• Counting mentions instead of origins: syndicated, translated or aggregated copies of one statement are one source.
• Treating a subject's filing and its own press release as two independent confirmations of a fact only the subject knows.
• Assuming that agreement proves truth; all sources can repeat one stale or wrong upstream figure.
• Treating a difference in definition or as-of date as a conflict.
• Making a fixed number of sources part of the definition.
• Recording "triangulated" without listing the sources and why they are independent.

Edge cases

• Two outlets that each interviewed the subject have one origin for what the subject said, even though the articles were written independently.
• A regulator's enforcement finding is independent of the filer's own filing, because the regulator reached it on its own evidence.
• The other party to a transaction (the manager for an LP's commitment) is independent of the subject for the transaction itself.
• Archived versions of one page across several years show the page's consistency, not independent confirmation.

Questions

Sources

1. Berkeley Protocol on Digital Open Source Investigations. OHCHR; Human Rights Center, UC Berkeley School of Law, United Nations (OHCHR) and UC Berkeley, HR/PUB/20/2; launched 2 December 2020; printed edition (c) 2022 United Nations. Status: Current (checked 2026-10-01). Paras. 176 (verification), 180 (independence), 191 (chronolocation), 193-194 (internal consistency, external corroboration) — supports: Verification by comparing source, item and content; independence of sources; corroboration
2. Intelligence Community Directive 203: Analytic Standards. Office of the Director of National Intelligence, ODNI, Signed 2 January 2015; technical amendments incl. 21 January 2022. Status: In force (as amended) (checked 2026-10-01). Sections D.6.d and D.6.e(1) — supports: Analysis based on all available sources, with source quality and credibility described
3. The effect of source reliability and information credibility on judgments of information quality in intelligence analysis. Megan O. Kelly; David V. Budescu; Mandeep K. Dhami; David R. Mandel, Judgment and Decision Making (Cambridge University Press), Vol. 20, e36 (2025); open access, CC BY. Status: Published (checked 2026-10-01). Table 1 — supports: Credibility grade 1 in the NATO system means confirmed by other sources

• Source Reliability
• Confidence Score
• Primary Source
• Open-Source Intelligence (OSINT)
• Data Provenance
• Entity Resolution
• Temporal Validity

• Precision and Recall