[Imports] [OpenSeaMap-develop] Fwd: NOAA Imports

[Serge Wroclawski]

I'm not in a position to understand the relevance or quality of the
data, but I do have some concerns about your method of confluence
based on the proposed import page:

> Add tag noaa:lnam derived from the S-57 LNAM field. This tag is the unique global identifier of this feature.
(and similar tags)

It's been my experience in working with various imports that this
method has problems.

Firstly, users modify tags in ways that don't seem rational. They
remove tags, they edit values, they edit keys. Therefore you can't
rely on those tags to exist, or to stay in tact.

And because your process relies on these tags, additional data made by
users themselves won't be discovered by your script, which means that
it will make duplicates, and that's not good.

Touching on that conflation further, are you saying in this proposal
that there is no data of this type other than by NOAA? Data that's
only available by a single source always concerns me, as it means that
there's no way for a regular user to be able to contribute. If that is
the case, then I think a much better way to handle this would be as a
data mixin, combining OSM data with NOAA data, rather than to import
the data directly in OSM.

I'm also wondering if this import would represent data that changes
frequently (more than once every six months). If so, then I strongly
suggest that this not be imported into OSM's core, but used in
OpenSeaMap (or something similar) alongside OSM, much like TopOSM uses
topological data alongside OSM. If you need help with this, we can
help you.

If the data can be contributed by other sources than NOAA, then your
process needs to have a way to conflate that data with yours, and not
create duplicates. Your argument that there's no current data makes
sense for now, but I think it should be addressed, especially as my
understanding from your page is that you'll be uploading on a regular
basis, so it may happen in the future.

Thirdly, about those tags, in my experience, while everyone things
that they're useful, it actually seems to dissuade editing. It's a
shame, and there's no "logical reason", but lots of users suffer from
the "It's official data, we shouldn't touch it" syndrome, and that's
not good for the project.

- Serge