👥Friend of a Friend

NEW

Also known as: FOAF

An RDF vocabulary describing people, their activities, and relationships to other people and objects for interoperable social data.

DESCRIPTION

FOAF provides terms to model persons, online accounts, documents, and relationships in RDF. It enables social graphs across sites through shared identifiers and properties. FOAF historically supported early linked data efforts; modern use often intersects with schema.org and vCard. It remains valuable for interoperability and legacy datasets. Clear modeling with FOAF promotes discoverability and linkage across the Web.

ALTERNATIVE DEFINITIONS

FOAF Vocabulary Specification

The FOAF vocabulary is a collection of terms for describing people, their activities and their relations to other people and objects.

Canonical description of scope and term coverage for FOAF.

Source

FOAF Project

FOAF (Friend of a Friend) is a project devoted to linking people and information using the Web.

Emphasizes the project’s goal: linking people and information on the Web.

Source

RELATED TERMS

RDF Vocabulary Knowledge Representation OWL Social Graph WebID Linked Data Person

COMPETING TERMS

Schema.org vCard

KNOWLEDGE AREAS

Semantic & Knowledge Modeling Data Integration & Interoperability Metadata Management

TARGET AUDIENCE

Software Developer Data Engineer Data Modeler Data Architect Information Analyst Data Steward

EXTERNAL SOURCES

• Wikipedia - FOAF (ontology)
• FOAF - Canonical FOAF vocabulary spec
• schema.org - Alternative vocabulary for people
• W3C - vCard RDF for contact data

TOP QUESTIONS

What does FOAF enable in linked data?

It standardizes person and relationship descriptions, allowing interoperable social graphs across systems using RDF.

Category: Overview

How does FOAF compare to schema.org Person?

FOAF focuses on social identity and relationships; schema.org targets web markup for search and broader entities.

Category: Alternatives

Is FOAF still relevant today?

Yes, for legacy datasets and interoperability; many modern systems use schema.org, but FOAF remains useful for social data.

Category: Relevancy

What are common mistakes when using FOAF?

Ambiguous identifiers, inconsistent URIs, and mixing FOAF with non-aligned vocabularies cause linkage issues.

Category: Mistakes

How can FOAF integrate with WebID?

Use FOAF properties to describe identities linked via WebID URIs for decentralized profiles.

Category: Example

What is the risk of poor FOAF modeling?

Fragmented identities and privacy concerns; apply governance and consent management for person data.

Category: Risk

Which tools support FOAF?

RDF libraries, graph databases, and ontology editors can model and query FOAF-based data.

Category: Platform

How do I start with FOAF?

Review FOAF spec, define identifiers (URIs), model persons and relations, test with SPARQL queries.

Category: Requirements

Can FOAF and vCard be used together?

Yes, FOAF for relationships and identity; vCard for structured contact details, both in RDF.

Category: Interoperability