{
  "name": "pisa-education-performance",
  "title": "PISA Education Performance",
  "description": "OECD PISA (Programme for International Student Assessment) mean performance scores for 15-year-olds in mathematics, reading, and science across 85 countries and economies, covering all cycles from 2000 to 2018. PISA is the world's leading cross-country standardised assessment of student skills, conducted every three years by the OECD.",
  "homepage": "https://www.oecd.org/pisa/",
  "version": "2018",
  "status": "structured",
  "licenses": [
    {
      "name": "CC-BY-4.0",
      "path": "https://creativecommons.org/licenses/by/4.0/",
      "title": "Creative Commons Attribution 4.0 International"
    }
  ],
  "sources": [
    {
      "name": "OECD PISA",
      "path": "https://www.oecd.org/pisa/data/",
      "title": "OECD Programme for International Student Assessment (PISA) — via World Bank EdStats"
    },
    {
      "name": "World Bank EdStats",
      "path": "https://datatopics.worldbank.org/education/",
      "title": "World Bank Education Statistics (EdStats) — PISA indicators LO.PISA.MAT, LO.PISA.REA, LO.PISA.SCI"
    }
  ],
  "resources": [
    {
      "name": "pisa-scores",
      "path": "data/pisa-scores.csv",
      "format": "csv",
      "mediatype": "text/csv",
      "description": "Mean PISA performance scores for mathematics, reading, and science by country and year (all students, age 15). Long format: one row per country × subject × year. Covers 85 countries and economies across 7 PISA cycles (2000–2018).",
      "schema": {
        "fields": [
          {
            "name": "country_name",
            "type": "string",
            "description": "Country or economy name (e.g. 'Finland', 'China (Shanghai)', 'United States')"
          },
          {
            "name": "country_code",
            "type": "string",
            "description": "ISO 3166-1 alpha-3 country code (e.g. FIN, USA, CHN)"
          },
          {
            "name": "year",
            "type": "integer",
            "description": "PISA cycle year: 2000, 2003, 2006, 2009, 2012, 2015, or 2018"
          },
          {
            "name": "subject",
            "type": "string",
            "description": "Assessment subject: 'mathematics', 'reading', or 'science'"
          },
          {
            "name": "mean_score",
            "type": "number",
            "description": "Mean PISA score for all students in the country/economy. Scale is standardised with OECD mean ≈ 500 and standard deviation ≈ 100."
          }
        ]
      }
    }
  ],
  "views": [
    {
      "name": "reading-scores-over-time",
      "title": "PISA Reading Scores by Country (2000–2018)",
      "resources": ["pisa-scores"],
      "specType": "vega-lite",
      "spec": {
        "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
        "transform": [
          {"filter": "datum.subject === 'reading'"}
        ],
        "mark": {"type": "line", "point": true},
        "encoding": {
          "x": {
            "field": "year",
            "type": "quantitative",
            "title": "Year",
            "axis": {"format": "d"}
          },
          "y": {
            "field": "mean_score",
            "type": "quantitative",
            "title": "Mean PISA Score",
            "scale": {"zero": false}
          },
          "color": {
            "field": "country_name",
            "type": "nominal",
            "title": "Country",
            "legend": {"labelLimit": 200}
          },
          "tooltip": [
            {"field": "country_name", "type": "nominal", "title": "Country"},
            {"field": "year", "type": "quantitative", "title": "Year"},
            {"field": "mean_score", "type": "quantitative", "title": "Score", "format": ".1f"}
          ]
        }
      }
    },
    {
      "name": "latest-math-scores",
      "title": "PISA Mathematics Scores 2018 — Top 30 Countries",
      "resources": ["pisa-scores"],
      "specType": "vega-lite",
      "spec": {
        "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
        "transform": [
          {"filter": "datum.subject === 'mathematics' && datum.year === 2018"},
          {"window": [{"op": "rank", "as": "rank"}], "sort": [{"field": "mean_score", "order": "descending"}]},
          {"filter": "datum.rank <= 30"}
        ],
        "mark": "bar",
        "encoding": {
          "y": {
            "field": "country_name",
            "type": "nominal",
            "title": null,
            "sort": "-x"
          },
          "x": {
            "field": "mean_score",
            "type": "quantitative",
            "title": "Mean PISA Mathematics Score",
            "scale": {"zero": false}
          },
          "color": {
            "field": "mean_score",
            "type": "quantitative",
            "legend": null
          },
          "tooltip": [
            {"field": "country_name", "type": "nominal", "title": "Country"},
            {"field": "mean_score", "type": "quantitative", "title": "Score", "format": ".1f"}
          ]
        }
      }
    }
  ]
}