The knowledge organization model
MatSci-SAM has a default vocabulary scheme, community vocabularies, shared tag schemes, and collections. A typed statement ledger records classification and relations between resources.
Vocabulary schemes and definitions
The default concept scheme is /vocabulary. Its HTML page also
lists community schemes at /vocabulary/{community}. A term is a skos:Concept
whose skos:inScheme identifies the owning vocabulary.
Two schemes may use the same preferred label for distinct concepts. Each term
has independent candidates and revision histories. skos:definition links
the term to the current revision of each candidate. Ordinary vocabulary work
retains the owning scheme.
Concept schemes
Tags are classification concepts shared across hosted vocabularies.
| Scheme | Classifies | Assigned by | Equivalent-term link | Order |
|---|---|---|---|---|
| Topics | Definitions | Definition author | Permitted | Preferred label |
| PSPP | Terms | Administrator | Not permitted | Processing, Structure, Properties, Performance |
Contributors can create topics. A topic attached to a definition is also
published on the containing term as a derived dcterms:subject statement.
Administrators may assign several PSPP facets to one term. The facet scheme
follows Greenberg et al. (2023).
A tag has a preferred label and may have alternative labels, a definition, and a scope note. The definition states meaning. The scope note guides classification. Broader and related relations connect tags within a scheme.
Equivalent topics and terms
A topic creator or administrator can link a topic to an equivalent term.
The one-to-one link is stored as skos:exactMatch from topic to term and
exported in both directions. The topic retains its identifier and displays
the linked definitions. The link is refused if the topic classifies a
definition of that same term.
Collections
A skos:Collection is a named, unordered set of terms. Each skos:member
assertion references an existing term, including terms from other vocabularies.
Membership leaves the term identity and owning scheme unchanged.
Administrator-created collections accept changes from administrators. Contributor-created collections accept membership changes from signed-in contributors when that creation mode is enabled. Retirement retracts active membership assertions and retains their history.
Statement ledger
An assertion records a typed subject, predicate, and object, with author and time. A retraction adds its author and time to that record.
| Relation | Predicate | Permitted resources |
|---|---|---|
| Classification | dcterms:subject |
Term or definition to tag |
| Hierarchy | skos:broader |
Terms in one vocabulary or tags in one scheme |
| Association | skos:related |
Resources of the same kind and scheme |
| Membership | skos:member |
Collection to term in any hosted vocabulary |
| External mapping | SKOS mapping properties | Term or tag to external IRI |
| Topic equivalence | skos:exactMatch |
Topic to term |
The export derives skos:narrower, the reverse of skos:related, term-level
topics, and the reverse topic-equivalence link from stored assertions.
Those derived triples have no independent assertion rows.
A collection reference records membership. An external semantic mapping requires its own assertion. SKOS and metadata specifies the RDF conventions, and the provenance model describes assertion history.