Schools — how this layer is made

What you are looking at

Each point is a school — a feature tagged `amenity=school` in OpenStreetMap. About 1.4 million of them worldwide, drawn as a coloured dot sized by footprint area and coloured by the level taught, where that has been recorded. At the closest zooms the dot is joined by the building's or grounds' mapped outline, where one has been drawn.

Click any school to see what OpenStreetMap records about it — its level, and who runs it where a mapper recorded that. Where the school has a Wikipedia article, a short summary is fetched live and shown in your own language; and every school links to the OpenStreetMap object it came from, including the ones with nothing else recorded.

Nurseries and kindergartens are not here — those are a different kind of feature in OpenStreetMap — and neither are colleges or universities, which have their own layers. The places of education layer shows all four together.

Mapped, not modelled

Each school is an object a mapper drew, from survey, local knowledge or aerial imagery; nothing here is modelled or estimated. The limitation is therefore completeness, not resolution: an unmapped school is absent, and on this map absence looks identical to empty ground.

Colour, and how much of it there is

Colour shows the level taught, and this is the layer's one real weakness: about four schools in five are not classified, and they are drawn in grey.

Level not recorded — 79.6% of schools
Primary — 13.7%
Secondary — 4.2%
Both primary and secondary — 2.5%

The level is read from three OpenStreetMap tags in order of how much we trust them: `isced:level` (on 19.0% of schools), then `school` (3.0%), then `education:type` (0.1%). Together they classify about a fifth of the layer. Nothing else on these features says more: `grades` is on 5.0%, `school:type` on 2.0%, `school:gender` on 1.0%.

There is no "nursery" colour, although OpenStreetMap does record nursery years on some schools. Almost every school marked that way also teaches primary — it is a primary school with a nursery class attached — so a nursery colour would have drawn 48,000 primary schools as something they are not. Standalone nurseries and kindergartens are a different kind of feature, and appear on the places of education layer.

Grey is therefore a real, named category on this map, and not a rounding error. It says nobody has recorded the level for that school — not that the school is unusual.

The coloured fifth is also not evenly spread. The tagging comes largely from bulk imports, so it concentrates in a few countries: 93.0% of Peru's schools carry `isced:level`, 87.5% of the Philippines' and 75.3% of the UK's, against 4.6% in the United States, 3.1% in France, 2.0% in India and 1.2% in Nigeria. Three countries holding 9% of the world's schools supply 41% of all the tagging. So the colours on this map partly show where an import happened. The dots do not: where the schools are is recorded by mappers everywhere, and that is what the layer is chiefly for.

The colours are ordered rather than merely distinct — light to dark up the levels, in the same teal the places of education layer gives its schools, so the same subject reads the same across the two maps.

Schools that teach both

A school teaching primary and secondary on one site — an English all-through school, an American K-12, a French cité scolaire — gets its own colour rather than being filed under one of its halves. It is a distinct kind of place to anyone choosing one, and OpenStreetMap records it plainly: the school simply carries both levels.

What a "school" is

`amenity=school` is OpenStreetMap's, and it does not map cleanly onto any one country's system. An English secondary school, a German Gymnasium, a French lycée and a US high school are all the same tag here. So this map shows a level of education, not a local school type, and comparing the mix of colours between two countries says as much about how each organises its schooling, and how its mappers tag it, as about the schooling itself.

Why we do not show whether a school is private

OpenStreetMap has an `operator:type` tag that is better covered than the level tags, and it is deliberately not used on this map. In OpenStreetMap `private` means the school is run by a non-government body. In English, "a private school" means one that charges fees. Those are not the same thing: an English academy is state-funded and free to attend, and run by a trust. Labelling it "private" would tell you something false about a real named school, so the tag is left out entirely rather than shown under a heading that misleads. Who runs a school is shown instead, by name, where a mapper recorded it.

Size

Each symbol is sized by footprint area — the ground the mapped outline covers, in square metres measured on the globe. Symbol area is proportional to footprint (radius to its square root), so a school four times the area draws twice as wide.

Many schools are mapped as a single point, with no outline and so no footprint. Rather than draw them all at the smallest size, they are given a nominal, typical size a little below the median footprint. Whether a school is mapped as a point or an outline is mostly a matter of how thoroughly it was mapped, not of how large it stands.

Footprint is physical extent, not importance, budget or number of pupils. A rural school with a large field draws larger than a city school with more pupils and no ground.

Places with no name

Not every school on this map carries a name, and the unnamed ones are shown just the same. A school with no name is one nobody has recorded a name for, not one that is not there.

Completeness

OpenStreetMap is not equally complete everywhere. Coverage is strongest in Western and Central Europe and other well-mapped regions, and thinner in low- and middle-income countries — which for this layer matters more than for most, because school provision is one of the things a reader might want to compare between rich and poor countries, and the map's own completeness runs along the same line. An absent school means "not yet mapped", not "does not exist". A dense patch here is a well-mapped place first, and a well-schooled one only second.

A picture of the present

Today's map, not a history. OpenStreetMap is edited continuously; this copy is refreshed periodically. There is no year control, and a school closed or merged long ago may still be mapped until a mapper updates it.