Tag: openstreetmaps

Facebook and OSM

The OSM global copy receives up to 5M changes every day, which means our local copy would quickly become outdated if we didn’t regularly update it. To reduce the risk of bad edits, whether intentional (vandalism) or unintentional, we don’t update our local copy directly. Instead, changes between the 2 versions are reviewed and accepted into the local copy. This all needs to be done on a regular cadence, or the growing difference between the global and local versions will require significant time and effort to catch up. We developed 2 new tools to help us keep pace: Logical changesets (LoChas) and our new machine-augmented automatic review system (MaRS).

LoChas break OSM changesets into individual CRUD operations and then cluster them for more efficient human review. MaRS uses a blend of heuristics and machine learning (ML) techniques to automate evaluation of LoChas that don’t require a further nuanced review. The ultimate goal of these tools is to create a funnel where machine-augmented techniques reduce the workload that requires human intervention.

OSM relicensing

The ideal situation would be that the ODC licences are suitable, and that not just the Foundation, but everyone involved in OSM agrees. If that’s the case, then we can publish the new terms without significant loss of existing data. If there are major objections, of course, we will either withdraw the proposal entirely, or weigh up the dangers of retaining the existing licence against the potential withdrawal of data. We are hopeful that the ODC licences are sufficiently in tune with the “spirit of OpenStreetMap” that this will not arise, but need to be alert to the possibility.

if they did not have such an inept license, many things would be possible. good luck with the relicensing dudes

Mapmaker Review

Google MapMaker is out. There are several geowiki projects, but when someone like google decides to have a go at the problem you have to take notice. First thing to note is that the MapMaker is open for a limited set of countries, one of which I have blogged about earlier. So let’s see what the uptake of MapMaker is by looking at Karachi (a city of ~20million, metropolitan and where locals are cultured with a strong entrepreneurial spirit) it appears there is very fast uptake from the locals. Here is what has happened in the course of a few hours

compared to OSM: superior UI -> superior results

OSM Army

I’m not convinced that the state of the art in GIS databases has appropriate answers. The OSM community, as ever, creates new cart-tracks across well-paved spaces. The debate is too heated for any but the really committed to follow, the tracks become effaced in debate, but perhaps they’re leading somewhere new. Or as the New Data Model paper puts it, Complexity does not mean that it has to be more complicated.

jo thinks the new OSM data model is more RDF-like, which of course she approves of

UK Flood Mapping

While OSM is a wiki with an archive, it doesn’t really handle change connected to specific moments in time. Roads are flooded for only so long. Here in Brighton, one of the core roads is reduced to one lane for a year while the Victorian Sewer is replaced. The changes need to be marked as impermanent. Also an issue in representing historic maps — I’m interested in producing historical literature maps of London, and that data needs proper tagging to show validity in only certain time slices.

makes the case that some of the flood data should be in the base map.