Re: [OSM-talk] OSM needs a measure for completeness
This would fit in very well with the annotation system discussed in the 'Recent Edits' thread not too long ago. -- martijn van exel -+- [EMAIL PROTECTED] -+- http://www.schaaltreinen.nl/ Op 3 feb 2008, om 20:16 heeft Dirk-Lüder Kreie het volgende geschreven: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Frederik Ramm schrieb: Whereever possible I'd like to try and have this completeness assessed by people *other* than those who did the mapping; maybe through a web interface where casual visitors can check their area of residence and rubber-stamp it (or note down complaints). I very much like this idea. Alongside with a simple way of correcting spelling errors without needing to go to any full-fledged editor. Of course there are some places that are spelt differently than many people would think. For example Neustadtswall vs Neustadtcontrescarpe The former is commonly referred to as Neustadtwall, for example. - -- Dirk-Lüder Deelkar Kreie Bremen - 53.0952°N 8.8652°E -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHphLzFUbODdpRVDwRAnbVAJ439+AdtQa9Tj4LkwCKevqgej64rgCgg2rD vL6Tc5jWyw29WBhH9VO5yMA= =XO1n -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
Chris Morley wrote: I have started a new thread with a measure for completeness in the title because this is an important topic for OSM. But the response to the recent posts quoted above, and my raising of it last July, has been only luke-warm. I've added http://wiki.openstreetmap.org/index.php/Straßenschlüssel to the wiki, a German description how to measure completeness: Completeness may be verified most easily for roads. Primary/secondary/.. are listed on most maps. The approach here is focused more on residential: 1) various sources for lists of roads: You may take names from city maps, get them from postal area codes, from telephone books, from address collections and many other sources. 2) encoding of valuable stuff There's a German system how an address may be encoded. It's based on the abbreviations which are used for car plates, an official key for the community, an official list of roads, the house number and the first letters of one's name. This official list of roads assigns a five digit number. This list does include especially all addresses where someone lives. Thus minor tracks or not necessarily included: The finer details differ from community to community. Roads outside the residential areas are not part of these lists. This encoding system is called FEIN or EIN. It is recommended by the police. The road lists (German: Straßenschlüssel) are used for other tasks as well (statistics, ownership, tax, maintenance, ...). The German cycling club (ADFC) uses this system for bicycle encoding as a matter of theft protection. That's why they offer a web service to obtain the personal EIN code for anyone: http://fa-technik.adfc.de/code/ein 3) opengeodb On the ADFC site there's a another web interface for the opengeodb data maintenance, which holds information about many places in Central Europe http://fa-technik.adfc.de/code/opengeodb.pl. These combined datas, the road lists and the opengeodb info, can be used to match OSM data and highway tags. The result is a certain measure of completeness, how many percent of those roads have been tagged by now. It does not include any other stuff that is worth tagging (where it may be more difficult how to measure completeness) and it does lack many tracks or details about the quality of the data (lanes, speed limits, total length etc.) Three larger federal states have been processed by now, see http://wiki.openstreetmap.org/index.php/Category:Statistics - Baden-Württemberg - Nordrhein-Westfalen / North Rhine-Westphalia - Bayern / Bavaria - Oberbayern - Niederbayern One result is a number in percent how many of those residential roads have been tagged. As another result, a second phase may be applied to identify incorrect spellings: see http://wiki.openstreetmap.org/index.php/Talk:Baden-Württemberg#Korrekturvorschläge (suggestions for fixes) I guess that road lists are available almost everywhere. Does anyone else do a match for larger regions, instead of the local area? - Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
[OSM-talk] OSM needs a measure for completeness
Some comments regarding the completeness thread: For Munich we currently use wiki pages to track the completeness: http://wiki.openstreetmap.org/index.php/Landkreis_M%C3%BCnchen (in German but Google translates it quite ok). Wiki pages were used because they are simpler to set up than anything else. It uses just a very rough scale as IMO a finer scale is not useful if the completeness is to estimated. The percentage values that are estimated usually do not tell much about the remaining effort. On the other hand the map can be devided in small areas ( 1/2 d effort) that can be easily evaluated. The tables just focuses on the most important things like street names, car navigation and bike navigation). I believe this is enough so that people will start using the map. It seems that not all mappers want to take the effort to enter areas into the tables. Most likely reason is that its not that simple to find the name for the area that has been mapped. Still its better than nothing. A good technical solution to assign completion-states might be similar to solution for the render-requests at tiles-at-home: When the user clicks a tile with some modifier keys a dialog appears that allows to select a completion level and to add some comments. This would also allow people without osm account to report errors. Grungelborz ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
What about one indicator of completness being automatic: How many key/value pairs per way or node. So you have the standard: this is claimed to be 80% complete by user:Bob (or this is validated to be 75% complete/accurate by user:Fred) Then you have addtionally: this as information to a level of 20% I'm not sure how the levels would work. Maybe 10% means ways have a highway value and a name value, nodes have a name value and something else, unless the node is attached to a way it doesn't matter. 50% means at least half of the ways/nodes have an additional 3 tags. Obviously it would need some work to get the levels defined right but hopefully you get the idea. Either the level definitions would have to be changed about once a year (due to tag proposals, more data being able to be entered), or they would have to be relative to the number of approved tags. On 13/01/2008, Lars Aronsson [EMAIL PROTECTED] wrote: Dair Grant wrote: Good point! Which makes it all the more important to have a mechanism for marking it as such, if only to reduce the number of people who make pointless trips to the middle of nowhere to confirm there's nothing there... There are very few places with nothing in them. There might be creeks or peaks or vegetation types. But what we can do is to define layers such as all secondary or bigger roads or all churches, cemetaries and memorial monuments and indicate whether these feature groups have been covered in an area. -- Lars Aronsson ([EMAIL PROTECTED]) Aronsson Datateknik - http://aronsson.se ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk -- Gregory [EMAIL PROTECTED] http://www.livingwithdragons.com ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
[OSM-talk] OSM needs a measure for completeness
David Earl wrote: I've said before and I'll say again: we need a way of asserting this area is complete (for one or more definitions of completeness). Andy Robinson (blackadder) wrote: The only way that we are going to individually or collectively state the completeness of a specific area is to carry out a verification process. It doesn't have to be done by third parties or even different contributors but it does need to be done by someone. We need a simple tag to display verification, perhaps the username and a date, say verification=blackadder_20080111 or similar. Martin Trautmann wrote: Is OSM that far that we need verification and quality ensurance? We are still far from completeness, which might be a primary goal. I have started a new thread with a measure for completeness in the title because this is an important topic for OSM. But the response to the recent posts quoted above, and my raising of it last July, has been only luke-warm. I wonder whether this is because completeness is associated in people's minds too closely with verification. As Andy has describes it in the (incomplete) quote above, verification involves individual accountability - I personally accept responsibility for the accuracy of this data. I don't think this is suitable for OSM at the moment; it may be necessary in the future if and when OSM becomes a serious alternative to commercial suppliers - but not yet. I, and probably others, are eager to make their contributions of as high quality as possible, but are wary about making a public and personal commitment to their accuracy. As is the case for all other mapping information, an assertion of completeness should only imply the best endeavours of the contributor, not a guarantee of 100% correctness. If you have ridden round a housing estate systematically and collected all the required information, you can reasonably say the area covered is complete. With this understanding, completeness would become part of routine mapping. It would encourage a systematic approach and the collection of any missed information. A possible detailed approach is as follows. A completeness boundary would be modelled on coastline: it would enclose an area, but would consist of many (ordinary) ways, with the completed area on the right. They would be tagged with one (or possibly more) definitions of completeness like major roads, public roads, public paths, which would be defined on a wiki page. Boundary ways would be moved or added on a day-to-day basis by anybody with local knowledge. An area might even have holes in it. Somebody would provide an overview map showing completed areas, and its animation would feature in most presentations on OSM. OSM really needs a measure for local completeness to demonstrate its progress externally. I hope enough people can be roused to discuss, and hopefully agree, the principles, before deciding on an implementation. Chris ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
On Jan 12, 2008 3:48 PM, Chris Morley [EMAIL PROTECTED] wrote: David Earl wrote: I've said before and I'll say again: we need a way of asserting this area is complete (for one or more definitions of completeness). Andy Robinson (blackadder) wrote: The only way that we are going to individually or collectively state the completeness of a specific area is to carry out a verification process. It doesn't have to be done by third parties or even different contributors but it does need to be done by someone. We need a simple tag to display verification, perhaps the username and a date, say verification=blackadder_20080111 or similar. Martin Trautmann wrote: Is OSM that far that we need verification and quality ensurance? We are still far from completeness, which might be a primary goal. I have started a new thread with a measure for completeness in the title because this is an important topic for OSM. But the response to the recent posts quoted above, and my raising of it last July, has been only luke-warm. I wonder whether this is because completeness is associated in people's minds too closely with verification. As Andy has describes it in the (incomplete) quote above, verification involves individual accountability - I personally accept responsibility for the accuracy of this data. I don't think this is suitable for OSM at the moment; it may be necessary in the future if and when OSM becomes a serious alternative to commercial suppliers - but not yet. I, and probably others, are eager to make their contributions of as high quality as possible, but are wary about making a public and personal commitment to their accuracy. As is the case for all other mapping information, an assertion of completeness should only imply the best endeavours of the contributor, not a guarantee of 100% correctness. If you have ridden round a housing estate systematically and collected all the required information, you can reasonably say the area covered is complete. With this understanding, completeness would become part of routine mapping. It would encourage a systematic approach and the collection of any missed information. A possible detailed approach is as follows. A completeness boundary would be modelled on coastline: it would enclose an area, but would consist of many (ordinary) ways, with the completed area on the right. They would be tagged with one (or possibly more) definitions of completeness like major roads, public roads, public paths, which would be defined on a wiki page. Boundary ways would be moved or added on a day-to-day basis by anybody with local knowledge. An area might even have holes in it. Somebody would provide an overview map showing completed areas, and its animation would feature in most presentations on OSM. OSM really needs a measure for local completeness to demonstrate its progress externally. I hope enough people can be roused to discuss, and hopefully agree, the principles, before deciding on an implementation. In a sense I'm already doing this. The very last thing I do when I've completed an area is to add landuse=residential (only where appropriate, of course). I could easily add complete=level-n to this landuse boundary. 80n Chris ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
Chris Morley wrote: I have started a new thread with a measure for completeness in the title because this is an important topic for OSM. But the response to the recent posts quoted above, and my raising of it last July, has been only luke-warm. I also think completeness is a very important idea - it's false to think that a map is ever going to be complete, but I don't think it's a good answer to say it can't be done. There are places in OSM where there is no data; these are obviously incomplete. Equally there are places in where the data is at least as good as any other map (bits of London say), subject to our data model (no house numbers, say). I wonder whether this is because completeness is associated in people's minds too closely with verification. As Andy has describes it in the (incomplete) quote above, verification involves individual accountability - I personally accept responsibility for the accuracy of this data. I don't think you accept responsibility for it in the sense of liability in case of mistakes, but as soon you as you enter some data into OSM you do accept some responsibility for it. You're responsible for ensuring that it bears some relationship to reality, that it didn't come from an illegal source, etc. As is the case for all other mapping information, an assertion of completeness should only imply the best endeavours of the contributor, not a guarantee of 100% correctness. If you have ridden round a housing estate systematically and collected all the required information, you can reasonably say the area covered is complete. With this understanding, completeness would become part of routine mapping. It would encourage a systematic approach and the collection of any missed information. Absolutely. I would be very happy if there was some way I could give a simple badge (or a score, 1-5, where 1 is empty and 5 is complete), to some area to indicate how done I thought it was. Both to myself as a way to keep track of what's next, but also so that other mappers can see just how much there is to do. A possible detailed approach is as follows. A completeness boundary would be modelled on coastline: it would enclose an area, but would consist of many (ordinary) ways, with the completed area on the right. They would be tagged with one (or possibly more) definitions of completeness like major roads, public roads, public paths, which would be defined on a wiki page. Boundary ways would be moved or added on a day-to-day basis by anybody with local knowledge. An area might even have holes in it. Somebody would provide an overview map showing completed areas, and its animation would feature in most presentations on OSM. I was thinking of a simpler model - each OSM account gets to define a list of bounding circles, and a 1-5 completeness rating for each circle. Circles rather than boxes, because completeness is by definition a fuzzy subject. Rather than trying to exactly cover the world with areas that are done/not done, it'd be better to just drop some approximate circles to cover smallish areas. These will all overlap and generally look a bit of a mess, but I think could be rendered in a way that would give you a sense of completeness in some area and demonstrate progress. E.g., at this point in time the areas that are complete should have more priority when rendering a zoomed out view - everyone knows that London will have lots of little holes in it, but in general most of the circles in there will be complete. When you zoom in then the incomplete areas become more important, so by the time you're at town/village level you want to be able to see which suburbs still need work to do. The only difficult bit is setting up the database to manage this information. I think it would be better done as part of the OSM user accounts, rather than in the OSM database, since I think putting it in the real data encourages us to try and over-specify something that's always going to be ambiguous. Periodically some software pulls all that information out and renders a map of it, or sends a message to any users with obvious contradictions (two circles share more than 75% of their area and their ratings are too far apart, or similar). -dair ___ [EMAIL PROTECTED] http://www.refnum.com/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
On Saturday 12 January 2008, Tom Evans wrote: David Earl wrote: I've said before and I'll say again: we need a way of asserting this area is complete (for one or more definitions of completeness). Chris Morley wrote: A possible detailed approach is as follows. A completeness boundary would be modelled on coastline: it would enclose an area, but would consist of many (ordinary) ways, with the completed area on the right. They would be tagged with one (or possibly more) definitions of completeness like major roads, public roads, public paths, which would be defined on a wiki page. Boundary ways would be moved or added on a day-to-day basis by anybody with local knowledge. An area might even have holes in it. Somebody would provide an overview map showing completed areas, and its animation would feature in most presentations on OSM. I like the idea, Me too. but agree it definitely needs the multiple (documented) definitions of completeness. Apart from some linear scale (e.g. 1-5 as suggested), I think we might also need some more specific approach for the areas covered by the AND and TIGER imports. Both will perhaps score 5 on the completeness scale for roads, but for example AND imported data needs some work to get it up to standard [1]. Also, most tracks and cycleways are not present. It would be nice to be able to say that for some area that (e.g.) - road data is from AND and partially verified; - major tracks and unsurfaced roads are added; - cycleways are complete; - amenities are not added. On the other hand, to be able to more easily render a nice map (overlay?) of completeness, it might be better to re-define the linear scale for these areas... (Which, I know, is perhaps not very nice.) [1] http://wiki.openstreetmap.org/index.php/AND-NL:_Todo Dutch todo list regarding data imported from AND. For example all ways not accessible by cars are tagged as highway=pedestrian. On a case-by-case basis this needs to be changed to e.g. footway, cycleway or left pedestrian. -- Freek ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
Hi, OSM really needs a measure for local completeness to demonstrate its progress externally. I hope enough people can be roused to discuss, and hopefully agree, the principles, before deciding on an implementation. I'm all for it but I would really try to deduce this completeness from external sources. For example: * Get statistics about paved roads in certain administrative areas, compare with OSM paved roads, arrive at a percentage of completeness. * Get population statistics and a good estimate for length of roads or ways per capita in the type of area you're looking at; use that to compute how many miles of road you should have and compare to OSM. * Get number of named roads for certain areas (even if the full lists might be legally problematic, it should be possible to call someone in the city administration and ask them for the *number* of roads at least!) and compare with OSM data. And so on. This will of course never be accurate but could help to draw coloured maps that give us an estimate of how good we're doing. Self-assessed detail complenetess (Personally went to this quarter and verified every road) is something that I see further down the road, and that will probably require some technical infrastructure. Whereever possible I'd like to try and have this completeness assessed by people *other* than those who did the mapping; maybe through a web interface where casual visitors can check their area of residence and rubber-stamp it (or note down complaints). Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00.09' E008°23.33' ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] OSM needs a measure for completeness
Frederik Ramm wrote: There are places in OSM where there is no data; these are obviously incomplete. How would you know ;-) there are places which are complete with nothing on them! Good point! Which makes it all the more important to have a mechanism for marking it as such, if only to reduce the number of people who make pointless trips to the middle of nowhere to confirm there's nothing there... -dair (although given enough pointless trips, you would create a de-facto footpath - problem solved! ;-) ___ [EMAIL PROTECTED] http://www.refnum.com/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
