Documentation

Here brief description of the models used when converting statistical classifications into RDF data. We are going to implement KXOS in our next release (May 2020). 

Central Product Classification v2.0 (CPC2.0)

The hierarchical structure of the classification is rendered by means of a the standard SKOS properties skos:narrower and skos:broader. Each item in the classification is an skos:Concept, with:

  1. an URI, which local part is the item's code 
  2. a title in English (skos:prefLabel)
  3. an explanatory note (skos:scopeNote

Central Product Classification v2.1 (CPC2.1)

The structure of this is version is very similar to v2.0, only slightly more complex. Main differences are in:

  1. the number of concept schemes
  2. the presence of "collections".

In CPC2.1, three concept schemes are defined:

  1. one concept scheme is for the items in the CPC2.1 "core"
  2. one concept scheme is for the items in the "Expansion for agriculture" defined by FAO and now published by UNSD as an Annex to the core CPC2.1. In order to be consistent with the usage of the "Expansion" in statistical daily life, this scheme includes all "expanded codes" (ie., the 7-digit codes proposed by FAO) and their parents up to the root of the classification (so as to enable proper aggregation of data) 
  3. one concept scheme is for the items specifically relevant to fertilizers. This scheme includes all items that are relevant to fertilizers, be those originally part CPC2.1 core (5-digit), or part of the expansion (7-digit), plus their parents up to the root of the classification (so as to enable proper aggregation of data)

Three groups of items (skos:collection) are also defined:

  1. only 7-digit items as proposed by FAO for the "Expansion"
  2. only items relevant to fisheries and aquaculture (as used by the FAO Fisheries and Aquaculture Department)
  3. only 7-digit items that are fertilizers and that are not included in the official "Expansion". This collection was introduced for internal use, to have an RDF representation of a possible future proposal to UNSD regarding the field of fertilizers.

Creditor Reporting System (CRS), Sector and Purposes

The hierarchical structure of the classification is rendered by means of a the standard SKOS properties skos:narrower and skos:broader. Each item in the classification is an skos:Concept, with:

  1. an URI, which local part is the item's code 
  2. a code (skos:notation)
  3. a title in English (skos:prefLabel)
  4. an explanatory note (skos:scopeNote

The two versions we have included have identical structure. Note though that the version from 2016 also included labels in Spanish, resulting form a work of translation done internally in FAO. 

    FAOSTAT Commodity List

    The original structure of flat list of items organized into groups is rendered as a two-level hierarchy (skos:broader/skos:narrower). Each item in the classification is a skos:Concept (groups of items are also skos:Concept), with:

    1. an URI, which local part is the FCL code
    2. titles in different languages (skos:prefLabel)
    3. the FCL code (skos:notation)
    4. mappings, to ISICRev 4, different versions of CPC, HS

    FoodEx2

    This RDF model adopted in this conversion was originally devised within a project run by the UK Food Safety Agency. In this model:

    1. Each main hierarchy of the classification is represented as a separate hierarchy, with specific narrower/broader relations (defined as subproperties of the standard skos:narrower and skos:broader), belonging to separate concept schemes
    2. Each set of facets is also a separate hierarchy belonging to separate concept schemes
    3. Items (skos:concept) may be part of more than one concept scheme
    4. items have a definition in English (skos:definition), and a scope note (skos:scopeNote)

    Forest Products Classification and Definitions (2016)

    The hierarchical structure of the classification is rendered by means of the standard SKOS properties skos:narrower and skos:broader. Items in the classification are skos:Concept, with:

    1. an URI, which local part is a numeric ID taken from the classification
    2. a code, assigned by the classification (skoks:notation)
    3. a title in English (skos:prefLabel)
    4. a definition in English (skos:definition)
    5. mappings to related classifications (ISICrev4, HS, CPC2.1

    Harmonized System

    This modelling differ from those adopted for all the other classifications, in that HS items from all versions (2007, 2012, 2017) belong to the same, plus one or more of the three skos:collection (one per HS version) in which they are valid. 

    Indicative Crop Classification (ICC) v1.0

    The hierarchical structure of the classification is rendered by means of a the standard SKOS properties skos:narrower and skos:broader. Each item in the classification is an skos:Concept, with:

    1. an URI, which local part is the item's code 
    2. a title in English (skos:prefLabel)
    3. a code (skos:notation)

    Indicative Crop Classification (ICC) v1.1

    No major differences in the structures of the two versions of ICC. 

    ISICRev4

    The hierarchical structure of the classification is rendered by means of a the standard SKOS properties skos:narrower and skos:broader. Each item in the classification is an skos:Concept, with:

    1. an URI, which local part is the item's code 
    2. a title in English (skos:prefLabel)
    3. a code (skos:notation)
    4. correspondences to other classifications (skos:closeMatch, skos:exactMatch)

    M49 (used in FAO) 2019

    Each geographical area is a skos:Concept and also an "entity type" as defined in a dedicated ontology. Each area has:

    1. an URI which local part is the M49 code
    2. (official) names in various languages (all skos:prefLabel)
    3. short names in various languages (properties from the ontology)
    4. dates of validity (properties from the ontology)
    5. different properties for codes in different coding systems (properties from the ontology)
    6. Membership of territories in larger areas is represented by means of skos:broader and skos:narrower. 

    Note: 

    • territories no longer existing are also included

    World Census of Agriculture Crop List v1.0 (WCA) 

    Entries in the list are given two types (rdf:type) - skos:Concept and dwc:Taxon. Each item has:

    1. an URI, which local part is English name of the item
    2. a scientific name and a common name, each rendered both with properties taken from SKOS and from Darwin Core (skos:prefLabel, dwc:scientificName and skos:altLabel, dwc:vernacularName respectively)
    3. a code (skos:notation)

    World Reference Base (WRB) 1998

    The 1998 version of WRB distinguishes 30 soil groups (each is an skos:Concept, skos:topConcept of the scheme). Each soil group has:

    1. as URI, which local code is a sequential number (representing the "order" of selection of the soil group)
    2. an English name (skos:prefLabel),
    3. a definition in English (skos:definition)
    4. 2-digit acronym (skos:altLabel),
    5. an order in sequence of assignement (wrb:hasOrder)
    6. a given number of qualifiers (each of them are skos:Concept), represented as children in the hierarchy (skos:narrower).

    Each qualifier has:

    1. an URI, which local part is a two-digit acronym
    2. an English name (skos:prefLabel)
    3. a definition in English (skos:definition)
    4. a property with numeric value (wrb:hasOrder) representing the order in sequence of assignement to the soil group.

    Note:

    • Not all qualifiers are actually used to qualify a soil group.
    • A qualifier may qualify more than one soil group. 
    • Planned improvement: distinguish the order of assignment of qualifiers for each respective soil group.