{
 "schema_version": 1,
 "metric_id": "J4",
 "name": "Adult literacy (PIAAC, OECD trend basis)",
 "domain": "J",
 "tier": "v1",
 "grade": "A",
 "frequency": "A",
 "harmonized_international": true,
 "caveats": "Three survey points in thirty years (IALS 1994, PIAAC 2012, PIAAC 2023) — no annual signal exists. Values are on the OECD's own trend basis: 2012 re-linked to the 2023 scale and language-barrier (doorstep) respondents excluded from both cycles — NOT comparable to the full-survey 2023 headline levels (literacy 279, numeracy 284), which include doorstep respondents first covered in 2023. The 2012→2023 literacy change (−1.7) is NOT statistically significant once the OECD linking error (3.27 score points) is added; OECD advises caution for IALS-era comparisons. Numeracy rose +7.4 points (significant, same basis) but its absolute endpoints are not published openly — stated on the page, not charted. Adaptive problem solving (2023) is a new construct, not comparable to 2012 problem solving. Next comparable point: 2029 (Cycle 2 Round 2).",
 "methodology_notes": "Built 12 Jul 2026; every value read first-hand twice (research agent + shipping agent) from the Cycle 2 report's free StatLink workbook (stat.link/4zgsuq, Fig 3.5 = Table A.3.23 (L); Fig 3.1 = Table A.3.1) and OECD Skills Outlook 2013 Table A2.2a/A2.6a (NL 2012: literacy 284.0, numeracy 280.3, both S.E. 0.7). No public OECD SDMX dataflow for PIAAC means exists (verified against the full dataflow list) — manual drop is the only machine-readable path. J5 (low literacy) folded in as page facts: 16% of 16–65-year-olds at Level 1 or below (OECD avg 26%); 2.2 million with low literacy and/or numeracy 16–65, ~3 million for 16–75 (PIAAC 2023 national report) — the older '2,5 miljoen' figure is Rekenkamer 2016 on PIAAC 2012, different age band (16+), do not mix.",
 "owner_review_required": false,
 "sources": [
  {
   "org": "manual:OECD-PIAAC",
   "dataset_code": "manual:J4",
   "licence": "OECD published data, cited with attribution"
  }
 ],
 "breaks": [
  {
   "period": "2012",
   "note": "IALS (1994) → PIAAC: OECD publishes this long-term comparison itself but advises interpreting IALS-era comparisons with caution"
  },
  {
   "period": "2023",
   "note": "PIAAC Cycle 2 redesign (tablet-based, reading/numeracy components scored into the scale): 2012 re-linked to the 2023 scale — trend tests carry a linking error of 3.27 score points; the −1.7 change is not statistically significant"
  }
 ],
 "primary": {
  "key": "manual:OECD-PIAAC|manual:J4|NL|score|basis=oecd-trend,domain=literacy",
  "dataset_code": "manual:J4",
  "source_org": "manual:OECD-PIAAC",
  "geography": "NL",
  "unit_code": "score",
  "dimensions": {
   "domain": "literacy",
   "basis": "oecd-trend"
  },
  "frequency": "A",
  "points": [
   {
    "period": "1994",
    "value": 285.8
   },
   {
    "period": "2012",
    "value": 284.0
   },
   {
    "period": "2023",
    "value": 282.3
   }
  ]
 },
 "series": [
  {
   "key": "manual:OECD-PIAAC|manual:J4|NL|score|basis=oecd-trend,domain=literacy",
   "dataset_code": "manual:J4",
   "source_org": "manual:OECD-PIAAC",
   "geography": "NL",
   "unit_code": "score",
   "dimensions": {
    "domain": "literacy",
    "basis": "oecd-trend"
   },
   "frequency": "A",
   "points": [
    {
     "period": "1994",
     "value": 285.8
    },
    {
     "period": "2012",
     "value": 284.0
    },
    {
     "period": "2023",
     "value": 282.3
    }
   ]
  }
 ],
 "peers": [],
 "derived": [],
 "trend": {
  "direction": "insufficient",
  "method": "OLS over last 8 annual observations, 5% significance (MBW convention)"
 },
 "deltas": {
  "latest_period": "2023",
  "latest_value": 282.3
 },
 "revisions_since": "2026-07-17",
 "generated_at": "2026-09-04T08:06:56+00:00"
}