Key Points
Introduction to Linked Open Data in the Humanities
The concept of IRIs
Introduction to RDF and Basic Modeling
- RDF is a W3C standard that gives a precise, shared format to the subject-predicate-object model.
- In RDF, every statement is a triple: subject, predicate, object.
- N-Triples is a notation for RDF: one triple per line, IRIs in angle brackets, statements ending with a period.
- The object of a triple can be an IRI (a resource), a blank node (an anonymous entity), or a literal (a concrete value like a date or string).
Serialization
- RDF graphs can be written in different serialization formats.
- Turtle is a compact and human-readable RDF serialization format.
- Turtle uses
.,;, and,to structure RDF triples. - Namespaces uniquely identify resources and properties.
- Prefixes shorten long IRIs and improve readability.
Model with Ontologies and Vocabularies
- keypoint1
From Model to Data
- OpenRefine with RDF-Transform turns a tabular mapping into RDF automatically, applying it to every row in the dataset.
- IRIs for entities should be constructed from stable column values, not row indices, this ensures that the same real-world entity always gets the same IRI across rows.
- A root node represents a subject entity; properties attached to it become predicates, and their values become objects, directly mirroring the triple structure.
- The same RDF graph can be exported in multiple serialization formats; Turtle is readable and compact, JSON-LD integrates with web development workflows.