Richard L. Zijdeman

Historical Vocabularies & Classifications

Co-author, HISCAM; maintainer, HISCO; convener of vocabulary work in CLARIAH

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.

Why it matters

Vocabularies and classifications are what let historical data from different archives, languages, and eras actually talk to each other — but they only survive if someone keeps maintaining them and keeps the right domain experts and developers coordinated around them. That coordinating role is easy to overlook next to the tools themselves, but it’s usually the difference between a vocabulary that becomes genuinely shared infrastructure and one that quietly stops being maintained after the project that built it ends.

Details

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

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