[talk-au] Victorian Vicmap Address Import Proposal

[Andrew Harvey]

On Mon, 24 May 2021, at 9:14 PM, Andrew Davidson wrote:
> Ideally, if we agreed that anything beyond addr:street was not 
> necessary, we would ask the iD developers to change the AU address 
> format to:
> 
> {
>      "countryCodes": ["au"],
>      "format": [
>        ["unit","housenumber", "street"],
>      ]
>    }
> 
> and it would stop asking users to enter the redundant information. This 
> would be a literal one line change to a configuration file.

Excellent point.

> > If we tolerate when mappers manually enter these, then I'd say
> > filling in these values is worth it, it shows the address as
> > complete, and prevents other mappers manually adding this information
> > we could have just imported anyway.
> 
> We've never had a discussion about this. Until last year we didn't have 
> a complete set of bounded localities, so people would have to put this 
> information in. Now that we've finished, people are wasting their time 
> if they do.
> 
> > If you are relying on the level 10 boundary for addr:suburb, that
> > means data consumers need to know that for Australia, addr:suburb
> > comes from admin_level 10. In other regions it might be different and
> > this information isn't really stored in OSM.
> 
> The first stop for data consumers would be to look at the Nominatim 
> address format configuration file.

>From what I can see Nominatim pulls any parent place=* or boundary=administrative area. Which is fine, even though sometimes these boundaries or places don't form part of the postal address, it's harmless for data consumers to display these.
> 
> I think we need to back up here and think about why you would import 
> address data into OSM. If we do this import then we'll get:
> 
> 1. A rendering of street numbers at high zoom levels.
> 2. Nominatim searches would be able to return results at the street 
> number level.
> 
> Both of which would be nice to have. However, if you were a downstream 
> data consumer, who was looking for street addressing data in Australia, 
> you would have three sources:
> 
> 1. Extracting address data from OSM.
> 2. Various state government address datasets.
> 3. G-NAF
> 
> I think we need to be realistic here. OSM is never going to be able to 
> compete with G-NAF. Because importing and updating the data will take 
> time and effort then the copy in OSM will likely be out of date, so a 
> data consumer is going to be better off pulling their data straight from 
> the source.

The way I see it OSM and GNAF are looking at addresses from a different lens. G-NAF (to me as an outsider) looks like a non-spatial postal address database where they decided to add coordinates to each of those address rows. OSM is mostly a database of real world features, where we attach address attributes to these real world features.

OSM has advantages beyond GNAF in that, these addresses are attached to an object, we can associate them with a business, an office, a building, an entrance to a building, the grounds of some place like a school.

In OSM we can directly fix errors in GNAF much faster than it would take GNAF to fix.

In OSM we can add proposed addresses before they are allocated.

Once the bulk of addresses are in OSM, it becomes easier to semi-manually add in new addresses as published from government sources.

So personally I feel that eventually OSM will be better than GNAF form most data consumers, unless you want the "authoritative" data then you use GNAF.

Back to the point about addr:suburb, addr:postcode, addr:state. I'm neutral, I can see arguments both ways, so I don't mind if we include them on each point, or if we exclude these, my analysis seemed to indicate it's safe to exclude them, software like Nominatim can and does correctly deal with addresses which have omitted these tags. I tried OSMAnd and it does seem to pickup the suburb from a parent boundary, and it seems to ignore postcode regardless of it being on a parent boundary, or addr:postcode next to the number/street.

Anyone else have any further views about including addr:suburb, addr:postcode, addr:state on each point or not?

Seb, are you still advocating including these tags?