The vocabulary everyone argues about, in one place with an owner
Taxonomies rarely fail because the hierarchy was wrong. They fail because nobody owns the terms, changes bypass review, and six systems each hold a slightly different copy. TopQuadrant manages concept schemes as governed assets - preferred and alternate labels, polyhierarchy, multilingual, and an editorial workflow with a named approver - so the vocabulary driving search, tagging, and retrieval is the agreed, current one.
Trusted to govern the data behind the world's most regulated decisions.
The modelling was fine. The governance was the missing part
A concept scheme without a workflow is a document anyone can edit and nobody is accountable for. That is where taxonomy programmes come apart: not in deciding whether a term belongs under two parents, but in the six months after, when three teams have each renamed it locally. Give each scheme an owner, route proposals to the person who understands that domain, record the reasoning, and publish one version.
One governed concept scheme per domain, where a term sitting under two parents is a single record rather than two copies that drift.
Of additions, merges, and retirements carry a named approver and the reasoning behind the decision.
Native concept modelling. Broader, narrower, related, and polyhierarchy are first-class, not columns bolted onto a flat list.
Concept modelling
How do you model a term that legitimately belongs in two places?
Most tools store a taxonomy as a folder tree: one parent, one child, one flat label. A concept scheme in SKOS holds preferred, alternate, and hidden labels, and as many broader and narrower relationships as the subject actually needs. A concept that sits under two categories is one record in two positions, not two copies quietly drifting apart.
- Preferred, alternate, and hidden labels per concept, each governed and versioned in its own right.
- Polyhierarchy without duplication. One concept, several valid positions, one definition and one owner.
- Related and associative links expressed as first-class relationships rather than free text in a notes field.
Labels and languages
How do you keep synonyms and translations attached to the same idea?
A vocabulary used in more than one language is usually several vocabularies drifting on separate schedules. SKOS labels are language-tagged properties of a concept, so the English preferred term, the French equivalent, and a retired English synonym kept as a hidden label all hang off one record. Change the concept and every language view moves with it.
- Language-tagged labels. Preferred, alternate, and hidden per locale, all on the same governed concept.
- Synonyms modelled, not buried. An alternate label is a governed value a search index can expand against.
- One source, many surfaces. Serve the right label for the consuming system's locale without a second vocabulary.
Editorial workflow
Who decides what a term means, and where is that decision recorded?
This is where taxonomies actually fail. A scheme with no workflow is a document anyone can edit and nobody answers for. Every addition, edit, merge, split, and retirement runs through a review cycle with a named proposer, a named approver, and the reasoning captured next to the change, so a decision made three years ago is still legible.
- Proposal and review. Changes are staged and visible before they reach the published scheme.
- A named approver per domain, so the person who understands the subject reviews it rather than whoever is online.
- Reasoning on the record. Why a term was added, merged, or retired sits alongside the change itself.
Change without breakage
How do you retire a concept without orphaning everything tagged with it?
Content tagged against last year's vocabulary still has to resolve this year, after a term is renamed, merged into another, or split in two. Concepts deprecate with successor relationships and old identifiers keep resolving, so existing tags do not become orphans. The same mechanism feeds search indexes and retrieval pipelines, which update with the vocabulary rather than failing quietly.
- Deprecate, do not delete. A retired concept stays resolvable and points at whatever replaced it.
- Merge and split with provenance. Which concepts were combined or divided, by whom, and when.
- Impact before the change. Every tagged asset, standing query, and downstream feed that references the concept, listed first.