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RE: BP restructuring: Metadata section

From: Linda van den Brink <l.vandenbrink@geonovum.nl>
Date: Fri, 29 Jul 2016 08:39:49 +0000
To: Joshua Lieberman <jlieberman@tumblingwalls.com>, "simon.cox@csiro.au" <simon.cox@csiro.au>
CC: "bcochrane@linz.govt.nz" <bcochrane@linz.govt.nz>, "andrea.perego@jrc.ec.europa.eu" <andrea.perego@jrc.ec.europa.eu>, "public-sdw-wg@w3.org" <public-sdw-wg@w3.org>
Message-ID: <13F9BF0BE056DA42BFE5AA6E476CDEFE725F439C@GNMSRV01.gnm.local>
From this discussion I take the point that ISO19115 should at least be mentioned in the BP. So I did; see BP1. 

-----Oorspronkelijk bericht-----
Van: Joshua Lieberman [mailto:jlieberman@tumblingwalls.com] 
Verzonden: woensdag 27 juli 2016 15:48
Aan: simon.cox@csiro.au
CC: bcochrane@linz.govt.nz; andrea.perego@jrc.ec.europa.eu; Linda van den Brink; public-sdw-wg@w3.org
Onderwerp: Re: BP restructuring: Metadata section

I would argue that we really haven’t had a good progression of profiles for 19115 that enable a good match between the need for metadata and level of effort to create it. We could look at RDF to help with that modularity.

Josh

> On Jul 27, 2016, at 12:13 AM, simon.cox@csiro.au wrote:
> 
>> I don't disagree to the limits of ISO 19115.  But it is current best practice. 
> 
> Yes - I agree. I think it is worth making sure this issue is raised from time to time, and the RDF technologies make mix-n-match much more open and tractable than UML and XML did. But my intemperate rant should not distract progress at this time. 
> 
> -----Original Message-----
> From: Byron Cochrane [mailto:bcochrane@linz.govt.nz]
> Sent: Wednesday, 27 July 2016 2:07 PM
> To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au>; 
> 'andrea.perego@jrc.ec.europa.eu' <andrea.perego@jrc.ec.europa.eu>; 
> 'l.vandenbrink@geonovum.nl' <l.vandenbrink@geonovum.nl>; 
> 'public-sdw-wg@w3.org' <public-sdw-wg@w3.org>
> Subject: RE: BP restructuring: Metadata section
> 
> Simon,
> 
> I don't disagree to the limits of ISO 19115.  But it is current best practice. And it is the worst possible approach - except for all the others currently existing, all of which also possess severe limitations.
> 
> Yes, we are all lazy and do not want to spend time documenting our work properly.  That does not mean it is not best practice.  I personally do not like the monolithic approach that is ISO 19115 and would prefer a RDF approach that has just the metadata you need when you need it and can be combined into a meaningful description of the resource.  That does not yet exist.
> 
> Mapping data has been notoriously difficult to document and catalogue long before it became digital.  There are too many indices and too great of provenance to capture to make it easy to categorize in a way that meets the needs of even a large plurality of users of a sizable collection.  I think satisfying none properly is where we start from.  The best we can hope for as far as I can see is to partially satisfy as many as possible.
> 
> Cheers,
> Byron
> 
> -----Original Message-----
> From: Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au]
> Sent: Wednesday, 27 July 2016 3:51 p.m.
> To: Byron Cochrane; andrea.perego@jrc.ec.europa.eu; 
> l.vandenbrink@geonovum.nl; public-sdw-wg@w3.org
> Subject: RE: BP restructuring: Metadata section
> 
>> Good metadata is first and foremost a tool that is necessary for good data management.  Search and discovery is secondary to this.  
> 
> This exposes the underlying problem. 'Metadata' fulfils a variety of functions. Search/indexing, discovery, attribution, lineage, quality, licensing and access controls, management, more ... While there is some overlap in the information needed to satisfy some of these functions, for some there is probably zero overlap except for the identity of the resource being described.  How realistic is it to expect a single record to satisfy all of these? ISO 19115 labours under this illusion, but usually ends up satisfying none properly ... 
> 
> -----Original Message-----
> From: Byron Cochrane [mailto:bcochrane@linz.govt.nz]
> Sent: Wednesday, 27 July 2016 7:06 AM
> To: 'Andrea Perego' <andrea.perego@jrc.ec.europa.eu>; 'Linda van den 
> Brink' <l.vandenbrink@geonovum.nl>; 'SDW WG (public-sdw-wg@w3.org)' 
> <public-sdw-wg@w3.org>
> Subject: RE: BP restructuring: Metadata section
> 
> Hi,
> 
> Jumping in here with  questions and comments about the role of 19115 in this.
> 
> Currently, the practice I am proposing here in NZ is that data creators and publishers capture metadata in ISO 19115 and publish GeoDCAT.  While GeoDCAT is great for search and discovery (two different things), it is only a subset of the 19115 standard.  For a more complete documentation of the dataset, ISO 19115 is still necessary.  But since 19115 is not (yet) linked data friendly, presentation in DCAT is a good best practice for publishing.
> 
> So I would suggest that the full best practice would be to capture metadata in ISO 19115 and present as GeoDCAT on the web.  This is the way that current GeoDCAT tools that I know of are designed to work.
> 
> Two further notions to throw out here, but not too sure how they fit.  Good metadata is first and foremost a tool that is necessary for good data management.  Search and discovery is secondary to this.  Also, I like to think of metadata, presented as HTML, as the natural landing page for datasets.  Not sure yet if the default landing page should be GeoDCAT or 19115.
> 
> Cheers,
> Byron
> 
> -----Original Message-----
> From: Andrea Perego [mailto:andrea.perego@jrc.ec.europa.eu]
> Sent: Wednesday, 27 July 2016 2:55 a.m.
> To: Linda van den Brink; SDW WG (public-sdw-wg@w3.org)
> Subject: Re: BP restructuring: Metadata section
> 
> Thanks, Linda.
> 
> I would be happy to help here, also with examples.
> 
> Some preliminary comments on the listed types of spatial metadata:
> 
>> data type (raster or vector)
> 
> Not sure if this completely matches with the ISO 19115 notion of "spatial representation type" - which is modelled with a code list including "grid", "vector", "text table", etc. - see:
> 
> https://geo-ide.noaa.gov/wiki/index.php?title=ISO_19115_and_19115-2_Co

> deList_Dictionaries#MD_SpatialRepresentationTypeCode
> 
> In any case, GeoDCAT-AP models this information by using adms:representationTechnique + URIs corresponding to the items in the ISO 19115 code list.
> 
>> Coordinate Reference System(s)
> 
> I've already mentioned the approach used in GeoDCAT-AP:
> 
> https://lists.w3.org/Archives/Public/public-sdw-wg/2016May/0072.html

> 
> The "link" between data and the relevant CRS(s) is made with dct:conformsTo - which is also in line with the use of such property in DQV to express conformance with a "standard".
> 
>> spatial resolution
> 
> As I said in another mail [1], DQV may offer a solution to this:
> 
> https://www.w3.org/TR/vocab-dqv/#ExpressDatasetAccuracyPrecision

> 
> The examples cover spatial resolution expressed as horizontal ground distance, equivalent scale, angular distance (which is how spatial resolution is expressed in ISO 19115 - we just miss an example on vertical distance).
> 
> 
> About making "spatial *meta*data indexable", is this going under BP1 as well? I think we have already good examples to include, also showing how this is a feature that can be (more or less) easily integrated in existing geo catalogue services and tools.
> 
> On this specific topic, I take the opportunity to mention that we started a mapping exercise between DCAT-AP + GeoDCAT-AP and Schema.org:
> 
> https://webgate.ec.europa.eu/CITnet/stash/projects/ODCKAN/repos/dcat-a

> p-to-schema.org/
> 
> One of the preliminary results of this work is: do we really need to map everything? Besides the fact that Schema.org does not include terms to model all what is in DCAT-AP / GeoDCAT-AP, the use cases addressed by these metadata schemas are different. So, the question is: what is really needed to be mapped to Schema.org to enable Web indexing and discoverability?
> 
> I think this is a general design issue about enabling the re-use of spatial data (not only metadata), that, in my understanding, was shown pretty clearly in the Geonovum testbed, where only a "simplified"
> version of spatial data and metadata is represented via Schema.org.
> 
> Cheers,
> 
> Andrea
> 
> ----
> [1]https://lists.w3.org/Archives/Public/public-sdw-wg/2016Jul/0164.htm

> l
> 
> 
> On 26/07/2016 14:47, Linda van den Brink wrote:
>> Hi all,
>> 
>> 
>> 
>> Finally, some progress. I’ve begun restructuring the Best Practices 
>> document based on the structure of the DWBP (same grouping and 
>> ordering of BPs). I shuffled all the BPs around to the best of my 
>> ability based on discussions we had in various places. I may have 
>> missed some insights because I find it difficult to keep track of all 
>> the mailing list discussions sometimes, so comments are more than 
>> welcome.  I’ve not started merging/consolidating BPs yet, but will do 
>> if appropriate. I’m working on them one by one, now.
>> 
>> 
>> 
>> http://w3c.github.io/sdw/bp/

>> 
>> 
>> 
>> In particular, I welcome more detailed comments on the section in the 
>> BP on spatial metadata. http://w3c.github.io/sdw/bp/#bp-metadata

>> 
>> 
>> 
>> I’ve got three BPs in that section at the moment.
>> 
>> 
>> 
>> The first one is about spatial coverage and other spatial descriptive 
>> metadata. Getting there, but needs examples at least.
>> 
>> 
>> 
>> The second is about CRS – there have been comments on this in the 
>> past as well as recent discussion, which I’ve tried to capture 
>> without making the section overly long or complex. Please review!
>> 
>> 
>> 
>> The third is on making the entities within a spatial dataset 
>> indexable (it was SDWBP25 in the FPWD). Even though this is not 
>> really a spatial but a general issue I’ve retained it for now, 
>> because it’s useful information and not detailed in DWBP. And even 
>> though it’s not clearly about metadata (at least not on dataset 
>> level), this section seems the best fit for it. Also, this BP needs examples and can probably be improved.
>> 
>> 
>> 
>> Your thoughts are appreciated!
>> 
>> 
>> 
>> Linda
>> 
>> 
>> 
> 
> --
> Andrea Perego, Ph.D.
> Scientific / Technical Project Officer European Commission DG JRC 
> Directorate B - Growth and Innovation Unit B6 - Digital Economy Via E. 
> Fermi, 2749 - TP 262
> 21027 Ispra VA, Italy
> 
> https://ec.europa.eu/jrc/

> 
> 
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Received on Friday, 29 July 2016 08:40:18 UTC

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