How to Classify Catalogs
Five questions on which data catalogs differ from each other, borderline cases, and how to record the classification of your own catalog.
Open Data Portals
National, city and international dataset portals. Who runs them, how they are built, what they run on and where they break.
Geoportals and Spatial Data Infrastructures
The most numerous type of catalog: what a geoportal consists of, who runs it, how it is built, what it runs on, how to check it and where it breaks.
Research Data Repositories
Repositories that accept research data for preservation, issue DOIs and make the data citable. Who runs them, what they run on and where they break.
Indicator Catalogs
Official statistics databases and indicator showcases. How series and breakdowns are organised, who runs them, what they run on, how to choose a platform and where they break.
Microdata Catalogs
Catalogs of censuses and surveys. How a study description is organised, what access levels exist, who runs such catalogs, what they run on, how to choose a platform and where they break.
ML Catalogs
Catalogs of datasets and models for machine learning, including hubs, competition platforms, collections and government AI data platforms. What they publish, what they run on and where they break.
Metadata Catalogs and Registries
Catalogs of vocabularies, code lists, data elements, descriptions of closed datasets and of other catalogs. How they are organised, who runs them, what they run on, how to choose a platform and where they break.
Dataset Search Engines and Aggregators
Services that collect descriptions from many catalogs and offer one search. Who builds them, how they work, what they run on, how to use them and where they go wrong.
API Catalogs, Marketplaces and Dataset Lists
Three small types on the edge of the notion of a data catalog, namely catalogs of programming interfaces, data sales platforms and simple lists of files. Who runs them, what they run on, where they break and when they are enough.
Comparing Types and Hybrids
A summary table of catalog types, how they differ in substance, what hybrids exist and how to build a site that does two jobs at once.