[Crm-sig] ISSUE 240: Start/End vs Period of Existence

Vladimir Alexiev vladimir.alexiev at ontotext.com
Wed Apr 23 02:57:23 EEST 2014

Martin> Use of an identifier and the floruit of a person is explicitly modelled in FRBRoo v2.0.

Thanks! I see it now (F51 Floruit)
- in BM we modeled Profession and Nationality as a group.
- It's interesting that Floruit has something very general: R59 had typical subject: E1 CRM Entity
- In contrast, F52 Name Use Activity has 
  R62 was used for membership in: E74 Group, and
  R61 occurred in kind of context: E55 Type
- If Floruit is modeled, surely Life merits to be modeled :-)
  Then again, it's a simple case of Floruit, one with e.g. 
  P2 has type: <being alive> a E55 Type, OR
  R59 had typical subject: <being alive> a E55 Type

> Yes, it is intentional that states that can only be
> acquired by explicit events, such as ownership, membership etc., are described
> by these events. This is to ensure monotonicity under increase of incomplete,
> but consistent knowledge.

After reading CRMgeo and these emails a couple of times, I now grok what's "monotonicity of states".
What I called "Periods of Existence" are Spatiotemporal Volumes.
These can be discontinous, right? One can start an activity, suspend it, continue it somewhere else, etc.
The monotonic accumulation of start/end events corresponds to potentially non-monotonic update of Spatiotemporal Volumes (split into smaller volumes, remove some part).
OWLIM rules are monotonic, so I agree with the goal to uphold monotonicity.

> events are the hooks for other, distinct, historically relevant information.
> Birth and death have quite different contexts and actors involved.

How about this Floruit: "Being a set and costume designer, a painter, an illustrator, and a poet in Russia and France in the first half of the 20th century 
[general fields of activity of Natalya Goncharova]"
Maybe it's interesting and historically relevant who helped her *become* a costume designer, and what caused her to *stop* being a costime designer?

I'm concerned that you end up with many ideosyncratic solutions, and no common pattern:
- E15 Identifier Assignment is two start/end events in one: deassignment of old identifier, and assignment of new one.
- F52 Name Use Activity is a period of use (spatiotemporal volume = period of continued use of an Appellation)
- both are subclasses of E13 Attribute Assigment

I find this confusing:
- If I say the time-span of F52 Name Use Activity is from 2000 to 2014, it means someone used that name for a period of 14 years.
- But if I say the same of E15 Identifier Assignment, it means whatever committee did this assignment, really took their sweet time and were in no hurry (14 years to decide ;-).
And I can attest that Josh at BM got confused, he thought assigned/deassigned of E15 somehow mean start/end, but they mean new/old

Or consider modeling the military service of <Binns> a Person in <USMC> a Group:
It can be done with these statements:
- <joining> a E85 Joining; P143 joined <Binns>; P144 joined with <USMC>; P4 has time-span [P82 "1963"]
- <leaving> a E86 Leaving; P145 separated <Binns>; P146 separated from <USMC>; P4 has time-span [P82 "1966"]
Or this one:
- <floruit> a F51 Floruit; P14 carried out by <Binns>; R59 had typical subject <USMC>; P4 has time-span [P82a "1963"; P82b "1966"]

- Monotonicity means that the <floruit> is stronger: also means there were no intervening leaving/joining between 1963-1966.
  If there were (like for this nicely moustached fella http://en.wikipedia.org/wiki/Henry_Pierson_Crowe)	
  then we'd need to model the Floruit as a discontinuous Period (having parts).
- <joining/leaving> are stronger than <floruit>, since joining/leaving express Membership, while R59 is only some general kind of relatedness.
  I'd say: John Dover Wilson's activity as a Shakespeare scholar (F51) R59 had typical subject William Shakespeare (F10)
  is quite different from: Ricardo Binns' activity as a USMC soldier ;-)
- R59 is not a subprop of P14 carried out by, nor P107 has current or former member.
  So if you want to query both, you need branches in your query, or Fundamental Relations to do it
- Note: R59 says it's Subproperty of:	
    P2 has_type / P92 brought into existence (was brought into existence by): E77 Persistent Item. 
    P2_has_type/ P94 has created (was created by): E89 Propositional Object.P129 is about (is subject of): E1 CRM Entity
  which is some confused property chain notation, but surely it can be stated explicitly too
- Most importantly, there's no way to relate these two styles

> True life-long observation is extremely rare, therefore
> most such states are concluded from events. If this is the case, these should be 
> documented, and not the states.

I think this is not borne out by actual documenting practice in many cases.
Maybe nobody checked if Binns was actually a soldier every month between 1963-1966,
or whether Leonardo actually painted every month during his career as a painter,
or whether the Maori actually used <particular Maori term> every month of <particular Maori era>,
or whether Michael Dukakis has been a member-in-good-standing of the ACLU ever since he joined.

But this won't stop biographers from making floruit statements, 
nor did it stop George H. W. Bush from accusing Michael Dukakis during the 1988 presidential campaign of being a "card carrying member of the ACLU"

>> "Modeling such Periods of Existence is significantly more economical than modeling with Start/End events. "
> This is no argument. Firstly, the size of all metadata together are a negligible fraction of image
> data we keep.

I mean firstly people economy, and only secondly computer economy.
Why do biographers make catch-all floruit statements? Because it's more economical, and it's generally/approximately true. (And life's too short.)

(Sorry can't resist: THAT is no argument. Image data is processed in fundamentally different ways from triples.
Or are you doing everything possible to get Cultural Heritage to classify under EC's Big Data funding lines? :-)

> Not all periods can have start or end events.
> What we need is an understanding of the semantics of "starting something".
> Is there an concept of cause or occasion? How does a start event behave in space-time?

It IS causative, and because of the causal-chronological coherence of time, we know how it behaves in time.

I'm not saying all periods should have start/end; nor all start/end necessarily need a period.
I am saying that CRM should offer a means to connect them (when present), causatively.
But, I'm not very good at topological epistemology (or whatever this should be called :-)

I'll try to check the other references you provided (but not CRMsci :-) within a week.

Cheers! V

PS: There is an old Italian proverb that says, "Everything has an end except salame which has two."
Because no matter which direction you start, it always ends!
Look here and salivate :-) http://blog.needsupply.com/2014/03/02/salami-friday/

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