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Re: SSN/SOSA/O&M: is an observation an event, activity, or information object?

From: Jeremy Tandy <jeremy.tandy@gmail.com>
Date: Wed, 24 Aug 2016 13:48:35 +0000
Message-ID: <CADtUq_1uMy0TkTYPp6npD6rsLpyT=PzVdwfo39z73nLxuvSeHQ@mail.gmail.com>
To: "Little, Chris" <chris.little@metoffice.gov.uk>, "Simon.Cox@csiro.au" <Simon.Cox@csiro.au>, "public-sdw-wg@w3.org" <public-sdw-wg@w3.org>
Simon- thank you for clearly stating the challenge.

Binding things back to PROV-O seems sensible; especially as it helps
clarify the disjoint definitions of Observation in OM and SSN. Referring to
the "must read" resource [1] that Simon identified ...

"""
PROV-O provides just three base classes: Entity, Activity and Agent.
om:Observation is sub-classed from prov:Activity, while ssn:Observation is
sub-classed from prov:Entity.
"""

For me, it seems natural to treat Observation as an Activity ... it's
something that's done at a particular time using a specified process. It
produces a some data (the result) ... the data, an information resource, is
an Entity. SSN seems unnecessarily complex in splitting the problem into
SensorOutput, Observation and ActivityOfSensing; OM does this in two
classes: Result and Observation.

At first glance the hierarchy Simon proposed in SOSA [2] seems sensible -
with top-level Classes of Procedure, Device and Activity. I'm lacking the
time to do a thorough road test of the complete hierarchy though. However,
I note that in OM the fact that OM_Process could describe anything from a
list of repeatable instructions (a recipe or sorts) through to an instance
of a sensor with a specific calibration has always been somewhat confusing.
It's good to see these concerns teased out into Procedure and Device,
recognising that a Procedure will often _use_ a Device.

HTH, Jeremy

[1]: https://goo.gl/TKlX1l
[2]:
https://www.w3.org/2015/spatial/wiki/index.php?title=SOSA_Ontology&oldid=2342#Procedures_vs_Devices


On Wed, 24 Aug 2016 at 11:07 Little, Chris <chris.little@metoffice.gov.uk>
wrote:

> Simon,
>
>
>
> Very helpful. Thank you.
>
>
>
> As an ontology ignoramus, I think “The result of an observation is an
> estimate of the value of a property of some feature” says it all. Whether
> there is one ontology (“to rule them all” as someone said) or two or three
> covering your different aspects consistently I leave to others to thrash
> out.
>
>
>
> Chris
>
>
>
> *From:* Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au]
> *Sent:* Tuesday, August 23, 2016 11:42 PM
> *To:* public-sdw-wg@w3.org
> *Subject:* SSN/SOSA/O&M: is an observation an event, activity, or
> information object?
>
>
>
> Kerry had asked me to discuss this in the SSN meeting today. We ran out of
> time, so here is a summary and some reading material.
>
>
>
> There are a lot of links below, so if you only have time to look at one,
> probably make it this: https://goo.gl/TKlX1l (and “Read the full
> publication”, which is just a set of slides).
>
>
>
> The problem
>
> ----------------
>
> The key concern is
>
> ·         SSN had the class “Observation” as a sub-class of
> dul:SocialObject. This is explicitly disjoint with dul:Event. So
> ssn:Observation appears to be a _*record*_ of an sensing activity, however
>
> ·         O&M http://portal.opengeospatial.org/files/41579 defined the
> concept:
>
>
>
> 4.11
>
> observation
>
> act of measuring or otherwise determining the value of a property
>
>
>
> and includes a class “Observation” which is introduced as follows:
>
>
>
> 7.1.2 Observation
>
> An observation is an act associated with a discrete time instant or period
> through which a number, term or other
>
> symbol is assigned to a phenomenon [2]. It involves application of a
> specified procedure, such as a sensor,
>
> instrument, algorithm or process chain. The procedure may be applied
> in-situ, remotely, or ex-situ with respect
>
> to the sampling location. The result of an observation is an estimate of
> the value of a property of some feature.
>
>
>
> So the word “Observation” appears to be used for two different things in
> SSN and O&M – a record, or an activity or event, respectively.
>
>
>
> Background resources
>
> ---------------------------
>
> See a presentation I made at last year’s AGU meeting “Pitfalls in
> alignment of observation models resolved using PROV as an upper ontology” -
> The presentation is on ResearchGate
> https://www.researchgate.net/publication/305809446_Pitfalls_in_alignment_of_observation_models_resolved_using_PROV_as_an_upper_ontology
>
>
>
> I also discussed the issue in my Semantic Web Journal paper “Ontology for
> observations and sampling features, with alignments to existing models”
>
> http://www.semantic-web-journal.net/system/files/swj1237.pdf - see
> particularly the discussion in section 5.
>
>
>
> In turn, these leaned on a paper by Mick Compton, David Corsar and Kerry
> “Sensor Data Provenance: SSNO and PROV-O Together at Last”
> http://ceur-ws.org/Vol-1401/paper-05.pdf
>
>
>
> Implementation in SOSA
>
> ------------------------------
>
> The initial SOSA-core took a related approach, with high-level classes for
> Procedure, Device, and Activity, which I introduced in an attempt to make
> the terminology around actuation, sensing and sampling consistent
>
> – see this version of the SOSA wiki page
> https://www.w3.org/2015/spatial/wiki/index.php?title=SOSA_Ontology&oldid=2342
>
>
>
> Subsequently this hierarchy has been removed from SOSA, partly because it
> was felt that SOSA-core was getting too big.
>
> But I wonder if this has merely kicked the can down the road. For me
> sorting the procedures, devices and activities for observing/sensing,
> actuating, sampling into these groupings clarifies things, but perhaps that
> just means I’m a stamp-collector.
>
>
>
> Issue tracker
>
> ---------------
>
> This topic is in the tracker as
>
> -          ISSUE-67: what is an ssn:observation
> https://www.w3.org/2015/spatial/track/issues/67
>
> And these are closely related issues:
>
> -          ISSUE-62: Align SSN with O&M
> https://www.w3.org/2015/spatial/track/issues/62
>
> -          ISSUE-53: Align ssn with prov-o
> https://www.w3.org/2015/spatial/track/issues/53
>
>
>
>
>
> Simon
>
>
>
> *From:* Kerry Taylor [mailto:kerry.taylor@anu.edu.au
> <kerry.taylor@anu.edu.au>]
> *Sent:* Monday, 22 August 2016 11:03 PM
> *To:* public-sdw-wg@w3.org
> *Subject:* sdw: ssn meeting this week
>
>
>
> Dear SDW,
>
> For the SSN meeting this week  *23 August 2016 21:00 UTC
> <http://www.timeanddate.com/worldclock/fixedtime.html?iso=20160823T21&ah=1&msg=SSN%20Call>*,
> the agenda as follows is proposed.
>
> Phil, Simon and Frans, please be prepared to lead respective topics with
> your name on it.  Frans – I can look after  action-111 if you are not
> present.
>
>
>
>    1. SSN: Issue tracking and public discussion (PhilA?)
>    2. UCR -- action-111 see
>    https://lists.w3.org/Archives/Public/public-sdw-wg/2016Aug/0084.html
>    (Frans?)
>    3. UCR - reviewing for SSN requirements issue-73 and
>    https://www.w3.org/2016/08/17-sdw-minutes#item05 (Kerry)
>    4. SSN/SOSA/O&M: is an observation an event, activity, or information
>    object? (Simon?)
>    5. Web of Things: joint meeting with oneM2M today
>    https://lists.w3.org/Archives/Public/public-sdw-wg/2016Aug/0070.html
>    6. Web of Things: meet at Lisbon, possibly
>    https://www.w3.org/wiki/TPAC2016/SessionIdeas
>
>
>
> More info:
> https://www.w3.org/2015/spatial/wiki/Meetings:SSN-Telecon20160823
>
>
>
> Kerry
>
Received on Wednesday, 24 August 2016 13:49:18 UTC

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