[HOT] re Validation queries
nick.allen.54 at gmail.com
Sat Jan 18 10:15:21 UTC 2014
Pierre & all,
I'm probably stating the obvious here, but..
When mapping some of the tasks which were created some months ago, &
then moved back into the feature list, I've noticed that the satellite
imagery has altered, and subsequently there can be a marked difference
in the buildings & road structure.
Which leads to, if a town is to be mapped & the whole task takes a
period of several months;
a/. Under the current system is it worth a review of existing work to
see if the older mapping should be reviewed & updated before marked as
b/. any new system needs to quickly allow a project leader to quickly
mark an entire area, not just a square, for review / remapping / or
Volunteer 'Tallguy' for
Mapping volunteer 'Tallguy' for http://www.openstreetmap.org
Treasurer, website & Bonus Ball admin for
http://www.6thswanleyscouts.org.uk/ (treasurer at 6thswanleyscouts.org.uk
<mailto:treasurer at 6thswanleyscouts.org.uk>)
On 18/01/14 08:25, Pierre GIRAUD wrote:
> Thanks Nick and Dan,
> I read your message carefully, and I agree with most of the things
> you've written so far.
> I agree that users don't get much feedback or even receive
> encouragement for their work on the map. They probably feel lonely.
> There already have been discussions on adding messaging features to
> the tasking manager. Kate have already tried to find funds for this
> However, this is still something I would like to see in the tasking
> manager. It's worth.
> For your information, I intend to merge what's been done on the
> "workflow" git branch which can be seen at http://tasks2.hotosm.org/.
> In this version, the workflow has changed a bit, with, I hope, a
> clearer interface. And with the ability to have a deep link for a
> given task in a read-only mode.
> In this version, I also decided to temporarily remove the "validate"
> button until we work on the more robust validation procedure. The
> "invalidate" button is still there though.
> Thanks again for your feedback.
> On Fri, Jan 17, 2014 at 10:12 AM, Dan S <danstowell+osm at gmail.com> wrote:
>> I think this is a lovely idea. I had the same sorts of anxiety as you
>> did, upon first joining in HOT tasks. To avoid email overload, perhaps
>> an email could be sent the very first time you get a square validated,
>> and from then on it would be possible just to see from the web
>> interface a list of the validation outcomes of your efforts. Of
>> course, the practical question is "who's going to implement it?" and
>> the answer is "no-one, unless someone keen on the idea has a go at
>> it", but personally I think this approach to the feedback loop for new
>> hot folks could be helpful.
>> 2014/1/17 Nick Allen <nick.allen.54 at gmail.com>:
>>> Not sure what I did with your original message - sorry, probably starting a
>>> new thread on the same topic, but this was the only way I could manage.
>>> Thank you for your detailed reply. It would indeed make a very good wiki
>>> article, and I would like to see that created soon, but possibly amended
>>> I do have a few other thoughts about the validation process though. My
>>> thoughts are from my own personal experience, and it would be good to obtain
>>> the views of several people, preferably fairly new to the system;
>>> When I first started mapping for HOT I found I was checking the squares that
>>> I had marked as complete on a regular basis. I was looking for some kind of
>>> confirmation that the work I was submitting had been checked
>>> and found to be of some kind of use. As an experienced 'mapper' I know that
>>> a lot of work I submit will be amended/refined in some way in the future by
>>> another mapper, but I felt that the validation which was
>>> obviously going to take place would provide some acknowledgement that I was
>>> producing something that moved the project forwards & wasn't hindering.
>>> Having looked back through the tasks I have been involved in, I can
>>> see that very few squares are actually marked as validated.
>>> Life experience has taught me there are circumstances where people can make
>>> quite serious mistakes by accident, or indeed deliberately sabotage a
>>> project, and I became concerned that this may not be discovered very
>>> Before I retired I spent many years working as a supervisor in an emergency
>>> control room, and found that the operators I was working with were keen to
>>> improve their capabilities, and prompt feedback & encouragement was
>>> extremely valuable for many reasons. In this work environment, the agreement
>>> between the supervisors was that we did not validate our own work, but that
>>> it was validated by another - thus avoiding as much human error as
>>> Obviously providing individual tailored feedback on each 'square' would be
>>> practically impossible, being extremely time consuming, and would probably
>>> cause offence amongst mappers who are experienced & devoted to HOT.
>>> Would it be possible, when a square is marked as validated, for some kind of
>>> auto generated message to be sent to the person who marked the square as
>>> complete - simple message something like
>>> "Thank you for the time & effort you have provided in mapping square xxxx on
>>> HOT task 326. This square has now been validated by another experience
>>> mapper. If there is any particular feedback it will be listed here:-
>>> Your further involvement in mapping areas in which relief organisations are
>>> working would be appreciated & welcome.
>>> Further information about the work of HOT can be found at ..............,
>>> and if you have not already done so, subscribing to ........... will give
>>> you more information & updates.
>>> Thanks again
>>> .............. (Validator)"
>>> The aim of this initial validation is to encourage new mappers to HOT to
>>> continue, and for preference should take place fairly soon after they have
>>> marked the square as complete. I accept that 'Fairly soon' can be a
>>> difficult/impossible target when vast quantities of mappers suddenly start
>>> work because a disaster is imminent or has just occurred, but feel that
>>> encouraging new mappers to continue should provide dividends in the long
>>> The option to not send the message should also be available, especially in
>>> the event of a long delay between mapping and validation.
>>> To be feasible would require that a number of people are willing to validate
>>> for part of the time they devote to HOT. It would be good to target the HOT
>>> tasks that have involved recent activity, such as those on the featured
>>> list, but care would be needed as some mapping took place when only poorer
>>> or older satellite imagery was available.
>>> In the event that information about who actually marked a square as complete
>>> is not available, perhaps the message could be sent to the individual(s) who
>>> have recently mapped in that square? Just marking the square as
>>> validated would provide enough encouragement for most people who continue to
>>> map with HOT, but the message gives you the opportunity to pass out
>>> substantially more information - not sure how to manage the communication
>>> with different languages though!
>>> I get a great deal of satisfaction from mapping, and would not want to
>>> validate all the time, but feel that using it as a tool to encourage others
>>> to continue aiding the project is worth trying.
>>> If the HOT members feel there is some merit in trying this, I feel it should
>>> be documented on the wiki, so that messages do not come as a surprise, or
>>> worry people because they think they are being singled out.
>>> Thanks for reading - sorry there is so much of my message!
>>> Nick (Tallguy)
>>> Thank you for your email. My answers inline.
>>>> Date: Sun, 12 Jan 2014 13:48:00 +0000
>>>> From: Nick Allen <nick.allen.54 at gmail.com>
>>>> To: HOT at openstreetmap.org
>>>> Subject: [HOT] Validation queries
>>>> Message-ID: <52D29D10.6010009 at gmail.com>
>>>> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
>>>> Would you like me to join in with the validation process? I am
>>>> experienced in mapping OSM, but am fairly new to regularly mapping HOT
>>> Would be great! Thanks for the proposition! Indeed you have contributed a
>>> lot in OSM. Mapping HOT projects is not very complicated, as you saw with
>>> it is less detailed then in developed countries, at least regarding remote
>>> mapping. Maybe the difficulty is when you do not know how those contexts
>>> look like. A goo way to compensate this is to look for videos posted on
>>> Youtube (examples
>>> especially the ones taken along road or streets. This is how you figure out
>>> if properties enclosures are walls, fences or hedges, what is often a
>>> cultural feature. Ah, just saw you mapped some wall enclosures (eg
>>> They actually are buildings (houses) under construction. It is frequent in
>>> developing countries that such works last a long time or even be abandoned.
>>>> I'm responsible for some of the mapping in
>>>> http://tasks.hotosm.org/job/72, as well as trying to change some of the
>>>> more obvious 'highway=track to highway=residential or unclassified etc..
>>>> or it may be easier to check what I've done using my OSM profile
>>>> How much validation is actually needed / done? Is it a proportion of the
>>>> whole task, or just until you are confident that, all things considered,
>>>> the task is fulfilled? You're never going to get 100% as some things
>>>> boil down to opinion about what the images actually are of, but the vast
>>>> proportion is pretty obvious.
>>> This is something that still needs to be settled and documented. I would
>>> say a validation is about both identifying mistakes/mapping lacks and
>>> standarzation/consolidation and has 2 or three steps, related to scale:
>>> 1. At neighborhood scale, check notably if:
>>> - buildings are missing. Sometimes it happens and if actually it
>>> represents a consequent number of building over a TM task, it can be
>>> - buildings are correctly traced. Hopefully it is not frequent, but
>>> sometimes mappers made really coarse outlines that do not respect either
>>> the buildings proportions or angle. More frequent are mappers that do not
>>> know how to square the buildings. In this case, after having checked what
>>> is their preferred editor, I generally send a message to their OSM
>>> box to give them the tip to do it
>>> - highway tags are correct. This is what you described. Some mappers put
>>> tracks wherever it is not a main road considering it is not paved, but
>>> is not a meaningful criteria in these developing countries considering
>>> of roads are unpaved.
>>> - road geometry. Some mappers do not put enough details and other too
>>> much (eg a node every 10 or 20 m even if the road is straight). First
>>> is quickly corrected with the (magical) Improve Way Accuracy mode in
>>> second case requires deleting extra nodes when they actually make weave a
>>> straight road.
>>> - start/end of roads. Some mappers are experts of giant snake roads or
>>> loop roads, Requires to pass the mouse over the streets to see their
>>> and cut them where it makes sense. On the contrary, some streets or roads
>>> are sawed without any reason (same tags for all the sections)
>>> - general issues of connections between objects. Some that should be
>>> connected and those that should not. Requires both Validator and also eye
>>> 2. at the town or city scale, it is quite related to the road network and
>>> its main highways. Having a larger view to identify the highways that are
>>> not simple residential roads. They are often larger and frame a larger area
>>> or can be a parallel way to main roads. It is also important to check where
>>> they start and when they stop, what is often not possible to do when you
>>> map with the Tasking Manager. This is what I tried to do with
>>> here are some examples of issues for Bangui:
>>> - missing parts of
>>> Looks weird on Mapnik and the check of the imagery confirms the two sides
>>> of the road separated by a drain are not finished
>>> - road
>>> The situation here seems weird as well as we expect the 2 unclassified
>>> roads to be connected and not joined by a simple path. The imagery
>>> that the southern highway looks the same, and should be tagged the same,
>>> whatever the tag. The example is actually good as farther
>>> it changes for tertiary. No reason for this, says the imagery. It should
>>> cut when it becomes a straight road, though
>>> - isolated upper-level road
>>> Drivable highways cannot be isolated and connected to the drivable road
>>> network by paths, they must be connected to it
>>> - tagging coherence
>>> in this example, the primary and tertiary road are connected by a
>>> unclassified road. Same thing between the two tertiary roads. After
>>> checked the imagery this road would deserve to be tagged as tertiary.
>>> obvious example apart, this requires to check the streets width to
>>> the main ones that needs not to be tagged as residential but unclassified
>>> or even tertiary.
>>> Hope this can help! I had in mind to give some tips and it became a start
>>> for a future wikipage :) Hope other people will read/discuss/complete this.
>>> Any constructive feedback from experienced HOT mappers is welcomed.
>>> Volunteer 'Tallguy' for
>>> Mapping volunteer 'Tallguy' for http://www.openstreetmap.org
>>> Treasurer, website & Bonus Ball admin for
>>> http://www.6thswanleyscouts.org.uk/ (treasurer at 6thswanleyscouts.org.uk)
>>> HOT mailing list
>>> HOT at openstreetmap.org
>> HOT mailing list
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