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talk · Tuesday 22 September · 11:15–⁠11:30 · SAL C

A knowledge organisation system for taxonomic data

Niels Klazenga · National & Global Taxonomic Backbones

Recording time 2:46:38–3:03:45Open on Vimeo ↗

Summaries and key moments are machine-produced. Check the recording for the speaker’s exact words.

The short versionSeparating taxon data into layers with immutable taxon concepts at the centre gives a practical path to implementing TCS and fixing checklist quality problems.

Overview

What this was about

Niels Klazenga argued that problems with taxonomic checklists are data-quality issues that are fixable, and presented a layered data model developed as a reference implementation for his flora following ratification of TCS 2 (Taxon Concept Schema) last December. The model separates concerns into semantics (taxon concepts), syntax (names, typification, usages), authority (references, agents), governance (taxon trees and revisions) and narrative (profiles), plus identity, infrastructure and extension layers, using 'sidecar' patterns to keep taxon concepts immutable. He mapped layers to TCS, Plinian Core and Darwin Core, noted that governance is not covered by any standard, and proposed a conceptual model for taxon data developed with the Darwin Core maintenance group.

Why it matters. Offers a concrete reference architecture for taxon-concept-based systems and identifies gaps (governance, conceptual model) in current TDWG standards.

Key ideas

In the room

  • TCS was ratified last December; reference implementations are needed for uptake.
  • Taxon concepts (scientific hypotheses) are central; names sit in a separate syntax layer, following David Remsen's distinction between syntax and semantics.
  • Authority (references, agents) links to all layers; governance holds taxon trees, nodes and revisions; narrative holds profiles and most flora content.
  • Identity (external IDs such as IPNI, Tropicos, MycoBank), infrastructure and extension layers support the system.
  • Sidecar extensions (name types, reference roles) and functional sidecars (tree node, profile) keep taxon concepts immutable.
  • Maps (name usages, relationships) are used in tabular data but are not entities with identifiers.
  • Phylogeny had to be core rather than an extension since it expresses domain semantics.
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Notable moments

In their words

Transcript

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Programme abstract

A Knowledge Organisation System for Taxonomic Data

Niels Klazenga

With the Taxon Concept Standard (TCS) now ratified, the community has a framework to better organize taxonomic data. While often designed for specific Floras, these models can serve as reference implementations for TCS and broader Knowledge Organisation Systems (KOS). This presentation introduces a model developed for VicFlora that is oriented around the Taxon Concept as the core of the system, with all other data layers acting as supporting components.

The model is structured across six key layers:

Semantics: Taxon Concepts and mappings Syntax: Names, relations, usages, and typification Governance: Taxon trees and versioned nodes Authority: Provenance (references) and attribution (agents) Narrative: Profiles and descriptions Identity: External identifiers.

To manage complexity, we employ a "sidecar" pattern. Extension sidecars manage name types and reference roles, while functional sidecars allow Taxon Concepts to remain immutable, while their context can change. By decoupling these, we can update classifications (via Tree Nodes) or modify descriptive content (via Profiles) without redefining the concept itself. The Profile serves as the primary extension point, bridging internal models with other TDWWG standards like Plinian Core, Darwin Core, and SDD.

We distinguish between narrowly defined relationships and polymorphic ones-such as provenance and attribution-which require flexible handling. This architecture provides a blueprint for building taxonomic systems that are theoretically sound under TCS and functionally agile, demonstrating how a concept-centric KOS can effectively integrate keys, maps, and occurrences.

Submitted to the conference programme before the talk, so the talk itself may differ.