choose a vocabulary and schema to descibe the catalog resources

In order to build a data catalog we need to decide upon what terms and schema we will use to describe the catalog resources, mainly the datasets.

I see two possible options

A: Data Catalog Vocabulary DCAT & DCAT-AP Application Profile

👍 recommended by Dutch and EU organizations( see https://data.overheid.nl/en/ondersteuning/open-data/dcat https://op.europa.eu/nl/web/eu-vocabularies/dcat-ap)

Data Catalog Vocabulary DCAT

Most relevant DCAT classes (for our data catalog context) :

dcat:Dataset
(implied) dcat:Catalog is collections of metadata about datasets, data services, or other resource types
- possibly:
  - dcat:Distribution represents an accessible form of a dataset such as a downloadable file. for representing dataset assets such as files
  - dcat:DataService represents a collection of operations accessible through an interface (API) that provide access to one or more datasets or data processing functions.

DCAT-AP Application Profile

the prime objective of the Application Profile is to enhance data findability and promote reusability. To achieve this goal, datasets should be coherently documented. To enable this, the Application Profile considers several essential aspects, including among others:

Understanding the data or service structure, and how to get access to the data Information on scope or purpose of the data Legal information Knowledge on data publishers, and any other agents involved Knowledge of data availability and change policies

an application that provides metadata MUST (relevant items for Ruisdael catalog):

(@andrecastro0o Bold - most relevant)

Provide a description of the Catalogue, including at least the mandatory properties specified for the class Catalogue. Provide descriptions of Datasets in the Catalogue, including at least the mandatory properties for the class Dataset. Provide descriptions of Distributions, if any, of Datasets in the Catalogue, including at least the mandatory properties for the class Distribution. Provide descriptions of Data Services, if any, of Datasets in the Catalogue, including at least the mandatory properties for the class Data Service. Provide descriptions of all organisations involved in the descriptions of Catalogue and Datasets, including at least the mandatory properties for the class Agent.

DCAT-AP Main entities: core classes and properties (mandatory/recommend)

Classes:

Agent - person or organization
- mandatory: name
- mandatory: type The nature of the agent. - Use: CV
Catalogue
Dataset |
- mandatory: description
- mandatory: title
- access rights
- contact point
- creator ,
- dataset distribution ,
- description ,
- documentation ,
- geographical coverage We might need to use instances of Geometry
  - For an extensive geometry (i.e., a set of coordinates denoting the vertices of the relevant geographic area), the property locn:geometry [LOCN] SHOULD be used.
  - For a geographic bounding box delimiting a spatial area the property dcat:bbox SHOULD be used.
  - For the geographic center of a spatial area, or another characteristic point, the property dcat:centroid SHOULD be used.
- identifier
- landing page ,
- ? provenance , publisher
- ?release date , sample ,
- ?source , spatial resolution ,
- temporal coverage ,
  - Property:period_start_date
- temporal resolution ,
- title ,
- type ,

Geolocation properties denoting a geo-point lat,lon,alt, or polygons, might need to include: what properties to use for those?

DCAT-AP diagram

controlled vocs for DCAT properties

See https://semiceu.github.io/DCAT-AP/releases/3.0.0/#controlled-vocabularies-to-be-used

B: DataCite Metadata Schema

👎 mixes terms and schema under 1 single XML (👎 👎 ) representation
- Q: isn't there a JSON/JSON-ld representation of the schema?
👎 does not differentiate between classes and properties (that's not how RDF based schemas or SMW(wiki) works)

See DataCite Mandatory Properties and compare to DCAT-AP classes + properties

ruisdael-observatory / Ruisdael-Data-Catalog