Folgert Karsdorp

Folgert Karsdorp · computational cultural evolution

Fragments of Cultural Change.

Most of what people once made, sang and told is lost. I study what survived, and estimate how much did not.

Each lit page is a publication. Hover to find one, click to take it out.Each lit page is a publication. Tap one to find it.

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Pen sketch of Folgert Karsdorp

I’m a researcher and head of the Ethnology, Everyday Culture & Society (EECS) department at the Meertens Institute of the Royal Netherlands Academy of Arts and Sciences, and Professor of Computational Methods for the Study of Cultural Change at Utrecht University. My research addresses questions about how culture spreads, develops, and disappears, drawing on computational and quantitative methods from ecology, population genetics, and machine learning, with particular attention to methodological challenges in analyzing biased historical collections and measuring cultural diversity and loss.

Worlds to walk through

Interactive reconstructions built from the collections I work with: you can walk through a corpus, a century or a statistical argument.

Little Red Riding Hood, her grandmother and the rest of the cast in a forest clearing at dusk, among drifting golden motes. Game · 427 tellings · 1781–2015 Roodkapje The Forest of Tellings Walk the forest as Little Red Riding Hood. Every fork in the path is a variant attested in 427 Dutch tellings, from 1781 to 2015, and the real words of those books keep you company along the way. Begin the tale Gerrit de Broen’s engraved map of Amsterdam, with red and blue song books stacked on the printers’ shops. Map & street · Dutch Song Database Op ’t Water Amsterdam’s song-book trade, 1600–1700 Every song book in the Dutch Song Database that names an Amsterdam printer, placed at the address in its imprint on Gerrit de Broen’s engraved map. Then step down onto the quay where the trade was busiest. Open the map Richness curves for two assemblages by sample size and by coverage, from the interactive demo. Simulation · coverage standardization Diversity under collection bias A companion to the Royal Society Interface paper Set up two assemblages, bias how their records were collected, and see which standardization strategy still recovers the true diversity ratio. Try the demo

Fragments

Notebooks on counting what the record leaves out: unseen species models, coverage, and the biases of the archives we inherit.

  1. Comparing diversity under collection bias An interactive companion to our Royal Society Interface paper on collection bias: set up two assemblages, bias how their records were collected, and see which standardization strategy still recovers the true diversity ratio. Interactive
  2. What Shall We Do with the Unseen Sailor? Applies unseen species models to VOC historical records to estimate the true number of sailors missing from the archive. 8 min read
  3. Estimating Unseen Shared Cultural Diversity Extends unseen species models to estimate the shared diversity between two cultural collections — how many artefacts they have in common that neither has observed. 11 min read
  4. Population Size Estimation as a Regression Problem Reframes population size estimation as a Bayesian regression problem to correct for heterogeneous detection probabilities in cultural samples. 12 min read
  5. Estimating Richness under Sampling without Replacement Examines how standard unseen species estimators break down under sampling without replacement, and how to correct for it. 10 min read
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