Russ, Replies in-line. I also mention my work in the DWG, but I'm not representing the DWG here, just reporting on what happened.
On Sat, Apr 4, 2015 at 12:31 AM, Russ Nelson <nel...@crynwr.com> wrote: > Brad Neuhauser writes: > > So, is the argument here that we should no longer delete features that no > > longer exist, just retag them? Is the argument that we generally should > > delete such features, but railways are a special case where we shouldn't? > > Yes, they are, because railroads went continuously from point A to > point B, and they leave their mark on the world. This is really the core of the issue. We're not talking about unused railroads, where the tracks remain, but ones where the track does not exist. > Maybe you don't see > it. Maybe I don't see it when I add a railroad=dismantled. But maybe I > can USE THE MAP to do field work to find it. But if you can't discover them while on the ground, eg if there's been a building placed over it, if the area has been paved over, or is now used as a field, then I see two problems: 1. It's not possible to validate 2.The railroad is no longer present, by definition Let's look at #1 in context. If there was once a battlefield in an area, but it's now a shopping center, what clues would I look for to determine that there was a battlefield here? If there were signs there, that might be doable, but in the absence of it, then I have don't know how I'd identify a battlefield from a regular field. Maybe an expert could. They could tell me that a certain land feature was indicative of a bunker being there once, but without training, I couldn't find it. As for the second problem, the way I see it is that a battlefield that's now a shopping center is now a shopping center in OSM. I don't think you'd disagree with me here, just as I don't think you'd disagree that a former playground in NYC that gets demolished and a tower put in its place is no longer a playground. > That's why I'm making a > fuss -- because having even dismantled railroads in OSM is > *useful*. It's useful to me, it's useful to railfans, it's useful to > rail-trail creators, it's useful to property managers, it's useful to > surveyors. I hear you. This is something you care deeply about, that you've put enormous sweat equity into in both time and effort, and you're concerned about your work being for naught. That's something I don't think anyone is forgetting, but in case you feel that it's being lost in the discussion, let me be as clear as I can in saying "Thank you for doing this hard work, Russ." That said, and not diminishing from it, the question before us is about whether or not this data belongs in this particular dataset, and utility is not the only measure we use. Propertly boundaries is something that people have wanted, and we've resisted putting in OSM, despite it being useful for a variety of people. Similarly, we've had people who wanted to put in sea routes which change weekly into OSM. That's also *possible* to map, but something that has been generally discouraged because despite its utility, is hard to verify. > I don't understand why people are so eager to delete accurate and > useful data, that people have spent hours, days, weeks, months, years, > and decades adding. I don't see people who are eagar to delete data. I see people who want to know what to do when they encounter a feature they can't see on the ground. The issue came to my attention because we had a user (User A) complaining about another user (User B) who had deleted a few dismantled rail lines. User A contacted the DWG regarding this and wanted User B to have administrative action taken against them. I looked at what User B did, looked at the changeset comments, looked at the discussions about it, and User B reports that they went to the area, manually surveyed it, created new data where there were unmapped features, and removed features which they could not see with boots on the ground. This area isn't anywhere near me, so I was stuck using the Bing imagery, but what I saw was that some of what was being deleted had other features on, such as houses where the rail line had been. In my capacity as a DWG member, I basically punted, saying "We have two users who are both acting in good faith. User A believes the railroads should stay despite no evidence on the ground, and User B believes that former railroads that don't have visible evidence should be removed." Both parties are are acting within what they believe to be community mapping standards for data in OSM, and neither one is acting with malice. In this thread, I see people basically playing out this same dispute. There's no consensus between groups on this issue- both parties are acting on what they believe to be good faith. My *personal* view is that OHM is a far better fit for this, because not only could you have the tracks, but you could capture data about them, such as what rail companies they used to serve, and what speeds they used to support. It makes a lot of sense to me to capture this incredibly useful data about the railroads. > I have pre-OSM GPS tracks from mapping old > railroads that date from 2002. I've added them, painstakingly, one at > a time, and joined them into the existing data as appropriate. I've > been mapping railroads since before OSM was a gleam in Steve Coast's > eye. > > If you want to know how serious abandonfans are, I've see people go > looking in farmer's fields with a metal detector looking for spikes, > and dig down 12" to find one. I've seen people go into a farmer's field > looking for chunks of coal that fell off coal trains. I've knocked on > people's doors to ask them if they know anything about the railroad in > their backyard. That shows an incredible level of dedication, but in OSM we generally don't require specialized equipment to contribute, including validation. > The evidence of dismantled railroads is out there, and it should be in > OSM to help people find it. What would you do about someone who was cleverly adding tracks that didn't exist? Imagine if there was a vandal who was clever. We'll call this vandal User V. User V decides to have a bit of fun and makes dismantled railroad ways. How do you propose we, as a community, handle User V? My normal way of handling such a matter, in or out of a DWG context, would be to go to the place and see if I see what they see. But my understanding from your mail (and you can correct me if I'm wrong) is that I personally have the expertise to make that determination? Who does? What makes one mapper more qualified than another mapper? This question gets to the heart of this project, which is that we don't make people take tests to map in OSM. This is such a generalist project that anyone can contribute. Now you're saying that, in essence, some features can only be evaluated by certain users. I don't think that's really what you mean, but that's what I'm hearing. Let me reframe the question. Instead of "Yes they should be in OSM" or "No they shouldn't be in OSM", here's the new question: If a user deleted an object that a layperson can't see in OSM, what do you think the process be for evaluating that edit should be? - Serge _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us