[Imports] City of Seattle imports

[Serge Wroclawski]

Jeff,

I've read this mail over several times, and simply find it hard to
parse. I don't know what email program you use, but standard email
in-line reply is > for a quote and >> for a quote of a quote. The
style you've adopted makes it hard for me to identify whose quoted and
in reponse to what

For more information on in-line quoting, see
http://en.wikipedia.org/wiki/Posting_style#Quoted_line_prefix

On Tue, Dec 4, 2012 at 6:53 PM, Jeff Meyer <jeff at gwhat.org> wrote:

> source tags are not really appropriate for indivdual elements,
>>> How do you identify when individual elements of the same way or node are
>>> derived from different sources?

One of the key important elements to understand about OSM is that OSM
is not a collection of sources, but is in fact a single unified
dataset.

Except in a few exceptional cases (which I'll address later) we do not
care that a features comes from one person or one source and not
another.

In fact, what's been shown is that "official" sources are a problem,
as people are hesitant to edit them, where we want people to be not
just be practically, but encouraged to edit. But when something is
stamped with "official" or from an external dataset, they're less
likely to.

Now, there are times when you want to know what source something came
from, and this is where changeset tags are far more useful.

For example, let's say there's a road, and someone adds it from some
local datasource. Someone else may look at the feature in imagery and
change its geometry. In that case, we'd like to know what imagery they
looked at.

But in OSM all of these techniques are considered secondary. Our
primary and always preferred method for data are people surveying. We
would always prefer, and should always favor a person on the ground
against other sources, and surveying doesn't have a "source".


>>>>> I didn't see any discussion or dispute of this approach on the wiki
>>>>> page, so I'm assuming it's ok.

This is a bad assumption. It's heavily debated, and largely deprecated
in favor of changeset tags.

I realize I addressed this above, but please, stop adding >>>>> to
your mails, this is odd and confusing.

> more importantly, the specific
> datasets should be referenced, as data.seattle.gov doesn't talk about
> the version of the data, or even what dataset it is.
>>> Good points. We will add these clarifications.

> Where is the source of your transformation scripts?
>>> From the email above: "some translation instructions Cliff has put
>>> together." We will include the specific translation code either at a github
>>> page or on the http://wiki.openstreetmap.org/wiki/Seattle page.

> Where are the specific data files you're transforming?
>>> They are at data.seattle.gov & we will provide links to the sources. We
>>> will also consider posting separate snapshots of these source datafiles if
>>> we can figure out where to host them.

Those scripts and datafiles need to be part of any discussion, as
early as possible.

> How will you handle object conflation?
>>> Manually and methodically.

Manually in that you will be adding all features by hand, you, yourself?

>>> Please identify any un-discussed concerns. I'd like to make sure we've
>>> accounted for them all.

Imports should generally not be done by those who do not have a long,
long history with OSM. Bad imports are not simply the same as bad
edits, but have long, multi-year consequences that communities
sometimes never dig out of.

What long time, trusted, local OSM community member do you have
working with you on this?

> but more generally, you seem to not have discussed this with the greater OSM
> community, including the talk-us list.

>>> I thought that imports@ was the "Greater OSM community."

See above.

>>> From the email above: "A group of Seattle OSM'ers (led by Cliff Snow) are
>>> getting together to discuss the methods for importing and double-checking
>>> the information.
> http://www.meetup.com/OpenStreetMap-Seattle/events/93524692/

>>> I will forward the prior notice to talk-us@

Discussion is better than notice, and imports isn't the greater US
community forum, talk-us is.

>>> advise as to the checklist steps we are not following, or which steps should
>>> be added to this checklist?

See above.

- Serge