What entity resolution means
Machines stitch identity from mentions. If your footer says "Acme Roofing LLC", your markup says "Acme Roofing" and your LinkedIn page says "Acme Roofing Inc.", a system reading all three has to decide whether they are one company or three. Entity resolution is that decision. When it goes right, the reviews, addresses and profiles of all three mentions attach to one entity. When it goes wrong, they split across several weaker ones, or attach to a different Acme Roofing.
You can't control every mention on the web. You can control your own: one name, one canonical URL with a stable @id, the same core facts everywhere, and explicit links that say which profiles are yours.
How each standard says "the same thing"
Standards give you several ways to say two identifiers mean one thing. They differ in how strong the claim is.
| Property | Defined in | Links | What the source says it claims |
|---|---|---|---|
owl:sameAs |
OWL 2 (W3C, 2012) | Two individuals | They "are the same individual (i.e., the same resource)" |
owl:equivalentClass |
OWL 2 (W3C, 2012) | Two classes | They "have the same class extension" |
skos:exactMatch |
SKOS (W3C, 2009) | Concepts in different schemes | "A high degree of confidence that two concepts can be used interchangeably across a wide range of information retrieval applications"; transitive |
skos:closeMatch |
SKOS (W3C, 2009) | Concepts in different schemes | "Sufficiently similar that they can be used interchangeably in some information retrieval applications"; not transitive |
schema:sameAs |
Schema.org 30.1 | Any thing to a URL | "URL of a reference Web page that unambiguously indicates the item's identity" |
| exact match (P2888) | Wikidata | An item to an outside URI | "A high degree of confidence that the concepts can be used interchangeably" |
| said to be the same as (P460) | Wikidata | Two items | The same, "though this may be uncertain or disputed" |
The OWL descriptions are quoted from section 10.6.8 of the SKOS Reference, which compares the two vocabularies. It warns that owl:sameAs "would typically be inappropriate" for linking concepts in different schemes, "because the formal consequences that follow could be undesirable": once two IRIs are the same individual, every statement about one becomes a statement about the other. That is why most websites use the softer schema:sameAs, pointing at profiles and reference pages.
How Wikidata keeps one entity's many names
Wikidata is a working example of entity resolution at scale: one item, one identifier, and every known name recorded on it. Here is how it stores the names of Google (item Q95):
| Field | Wikidata's rule | On Q95 (13 November 2026) |
|---|---|---|
| Identifier | Items are identified by "a Q followed by a number" (Introduction) | Q95 |
| Label | "The most common name that the item would be known by"; no two items may have both the same label and the same description (Help:Label) | |
| Description | Tells items with the same label apart | American multinational technology company, a subsidiary of Alphabet Inc. |
| Aliases | "Alternative names, like nicknames, acronyms, or translations", as many as needed (Help:Aliases) | None in English |
| official name (P1448) | "Official name of the subject in its official language(s)" | "Google LLC" at preferred rank; "Google Inc." at normal rank |
| short name (P1813) | Short name of a place, organisation or person |
Ranks do the rest. Wikidata's Help:Ranking says the preferred rank goes to "the most current statement or statements that best represent consensus", the normal rank is the neutral default, and the deprecated rank is for statements "known to include errors" or outdated knowledge. On Q95, "Google LLC" is the preferred official name and "Google Inc." stays on the item at normal rank. The earlier name is kept and ranked, not deleted, so a system that meets "Google Inc." somewhere can still match it to the same item.
What to do on your own surfaces
- One name, written identically. Pick the exact spelling, capitalisation and legal suffix, and use it on every page and profile.
- One canonical URL and
@idper entity. Every page that mentions the company points at the same@id. - The same core facts. Address, phone and founding date match wherever they appear.
- Explicit links. List your real profiles in
sameAs. If an old name is still out there, record it asalternateNameinstead of letting it float free.
Sources
All checked 13 November 2026:
- W3C, SKOS Simple Knowledge Organization System Reference, Recommendation, 18 August 2009, sections 10.1 and 10.6.8
- W3C, OWL 2 Web Ontology Language Document Overview (Second Edition), Recommendation, 11 December 2012
- Schema.org, sameAs, version 30.1
- Wikidata, Q95, properties P2888, P460, P1448 and P1813
- Wikidata, Introduction, Help:Label (last edited 17 April 2026), Help:Aliases (last edited 10 July 2026) and Help:Ranking (last edited 26 October 2026)
Next step
See why any of this decides what a machine says about you: why it matters.
Frequently asked questions
- What is the difference between owl:sameAs and schema.org sameAs?
- owl:sameAs states that two IRIs name the same individual, with formal consequences in OWL. Schema.org sameAs points from a thing to the URL of a reference page, such as a Wikidata entry or official website, that unambiguously indicates its identity.
- Is skos:exactMatch transitive?
- Yes. The SKOS Reference declares skos:exactMatch transitive and a sub-property of skos:closeMatch. skos:closeMatch is not transitive, to avoid compound errors across several concept schemes.
- How does Wikidata tell two items with the same name apart?
- By the description. Wikidata's label guidance says items can share a label, but no two items may have both the same label and the same description.