The OpenStreetMap database has been getting enriched with Wikidata tags on a daily basis, with over 500,000 feature tagged till date. This is generally done based on matching the name and location of a popular map feature to its corresponding Wikidata item if it exists. Check the OSM Wiki page on Wikidata for more information.

This is currently done manually and requires local knowledge to avoid connecting unrelated features between the two databases. The most common case of mixup are:

• Features with the same name exist and lie in entirely different geographical area eg. City named Salem in US and in India.

• Features with the same name but of a different type in the same location eg. A railway station matched to a nearby landmark of the same name

In such cases, there are high chances of linking wrong wikidata items to OSM feature if one doesn’t match the locations of both features correctly. Apart from this, there happens a lot of human error in copy pasting the wrong wikidata QID. The following post introduces a validator tool for reviewing these mismatches based purely on location.

Validating wikidata tags in OSM features using wikidata-osm validator.

wikidata-osm is a visual validator tool which spots possible Wikidata tag mismatches by comparing the location of the OSM and Wikidata feature and highlights those where the distance between these is greater than threshold distance set by the user.

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I decided to spend some time mapping on OpenStreetMap after starting at Mapbox to help build better mapping tools later. After having show and tells with Mapbox buddies, I started off with mapping my hometown. Though I had not very perfect memory of the places in my hometown as I am away from it from many years, but there were few places which I was sure about. As it is advised to add data with 100% accuracy only, therefore I tagged only the sure places in OSM. When I downloaded the data for my city Gandhidham in JOSM, to my surprise, the city was well traced by a remote mapper. Therefore I worked on adding known POIs. It was fun to look for my home from the satellite imagery and tag its address.

Next I traced roads in city called Raipur. It was like taking part in an enjoyable drawing task while keeping a few rules in mind. Adding intersections, junctions, classification of roads has a huge impact on the routing. So I did that quite carefully.

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What is Mapping?

It is an operation which associates elements of one set with the one/more elements of another set. When we talk about mapping in OpenStreetMap, the similar concept is followed. In that, we associate the real life objects (Home, Parks, Schools, Roads, Water bodies) to 2D elements like node, ways and polygons. This means that we can traverse any place virtually by looking at the map and can a get a sense of directions, locality, etc.

What are the objects which can be mapped?

It can be mapping different amenities, POIs, roads, buildings, water bodies, turn restrictions, different transport networks, Trees, Street lamps, so on. This list is never ending as each of them has a special purpose of being added in the map. The more detailed it is, the more it helps in understanding the place geographically.

How do we Map?

Basically there are two steps involved to map a place:

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