{
    "$schema": "https://highvaluedata.net/fair-data-schema/dev",
    "$id": "https://highvaluedata.net/fair-data-schema/dev/examples/variable-cascade",
    "title": "Comprehensive Variable Cascade Example",
    "description": "A 'Master Example' showcasing all aspects of the Variable Cascade: internal chaining, external authority mapping (DDI, Croissant, Schema.org), and the hierarchy of Unit Type, Universe, and Population.",
    "type": "object",
    "fair:universe": "General population of Iceland",
    "fair:universeRef": "https://wikidata.org/wiki/Q189",
    "fair:temporalCoverage": { "start": "2024-01-01", "end": "2024-12-31" },
    "fair:spatialCoverage": "Iceland",
    "$defs": {
        "CONCEPT_EMPLOYMENT": {
            "title": "Conceptual: Occupational Status",
            "description": "The phenomenon of economic activity.",
            "fair:conceptRef": "https://www.wikidata.org/wiki/Q156371",
            "fair:unitType": "Person",
            "fair:unitTypeRef": "https://www.wikidata.org/wiki/Q5"
        },
        "REPRESENTED_EMPLOYMENT_BINARY": {
            "title": "Represented: Active/Inactive Binary",
            "description": "A shared coding scheme for employment status.",
            "fair:conceptualVariableRef": "#/$defs/CONCEPT_EMPLOYMENT",
            "fair:universe": "Adult human beings of working age"
        }
    },
    "properties": {
        "q1_age": {
            "title": "Age (External DDI Instance)",
            "description": "Full formal mapping where a dataset-specific variable points to an external registry.",
            "type": "integer",
            "fair:instanceVariableRef": "https://agency.is/vars/q10_a",
            "fair:conceptRef": "https://www.wikidata.org/wiki/Q185836",
            "$comment": "Tools find 'Person' (Unit Type) and 'General Pop' (Universe) by traversing the external URI."
        },
        "q2_employment": {
            "title": "Employment (Internal Pure Cascade)",
            "description": "Lineage built entirely within the schema using internal references.",
            "type": "integer",
            "fair:representedVariableRef": "#/$defs/REPRESENTED_EMPLOYMENT_BINARY",
            "fair:population": "Adult residents of Iceland",
            "fair:populationRef": "https://agency.is/vocabs/pop/Iceland-Adult-2024"
        },
        "q3_satisfaction": {
            "title": "Satisfaction (MLCommons Croissant)",
            "description": "Mapping to a Croissant 'Field' definition (treated as an Instance level definition).",
            "type": "integer",
            "fair:instanceVariableRef": "https://croissant-registry.org/datasets/feedback/fields/satisfaction",
            "fair:label": "Overall life satisfaction"
        },
        "q4_pop_count": {
            "title": "Population (Schema.org StatVar)",
            "description": "Mapping to a Schema.org 'StatisticalVariable'.",
            "type": "integer",
            "fair:instanceVariableRef": "https://schema-registry.org/statvars/PopulationCount",
            "fair:universeRef": "https://schema-registry.org/places/World"
        },
        "q5_voter_status": {
            "title": "Voter Status (Standalone Annotation)",
            "description": "No variable record; just flat annotations for population and phenomenon.",
            "type": "boolean",
            "fair:universe": "Registered voters in Iceland",
            "fair:conceptRef": "https://www.wikidata.org/wiki/Q110609353"
        }
    }
}