Richard L. Zijdeman

Historical sociologist studying inequality and builder of the infrastructure that unlocks archives for research.

I'm a historical sociologist at the International Institute of Social History. My research traces long-term trends in social inequality, occupational stratification, and gender segregation in the labour force, mostly through archival sources like marriage records and censuses. I also build the infrastructure that makes that kind of research possible — as director of the HSNDB, co-PI in SSHOC-NL and chairing the national coordinators within DARIAH, the European research infrastructure for arts and humanities.

Recently — infrastructure

dataLegend

The linked-data ecosystem behind CLARIAH’s structured historical data — datasets, the tools to publish and query them, and the stories built on top of them.

What it is

dataLegend is CLARIAH’s ecosystem for everything linked data: a triplestore (Druid) hosting historical socio-economic datasets as RDF, tools to create and publish Linked Open Data, grlc for turning stored SPARQL queries into shareable REST APIs, and Data Stories — narrative pages built directly on top of live linked datasets rather than static exports. In CLARIAH-NL’s newer projects, SSHOC-NL and Macroscope, we continue building on this ecosystem: a knowledge graph of CLARIAH tooling connected to the SSHOC Open Marketplace, and an open version of Data Stories.

rev 1598be5 · updated 26 Jul 2026 · “Rewrite Structured Datahub entry as dataLegend”

Historical Vocabularies & Classifications

Vocabularies and classifications that let historical data — occupations, places, people — be compared across archives, languages, and eras.

What it is

I co-authored HISCAM, the continuous social-stratification scale built from occupational co-occurrence, and I maintain the HISCO occupational classification files — including publishing them as Linked Open Data so they can be queried alongside other historical datasets rather than passed around as static lookup tables. Beyond HISCO, I support and contribute to other vocabularies for historical sources: NLGIS, which standardizes historical Dutch administrative geography, and more recently Persons in Context, a model for representing historical person records as linked data. Within CLARIAH, I’ve been instrumental in setting up work on vocabularies more broadly, including a recommender tool — my contribution there is less about building the tools myself and more about convening the people who do.

rev ed9f47a · updated 26 Jul 2026 · “Populate site with real content and generate CV”

Recently — research

From Linked Open Data to Collections as Data: A Reproducible Framework Using Federated Queries

Persons in Context. A Model to Represent Observations and Reconstructions of Historical Persons in Linked Data

All research →   All infrastructure →