Issue 609: Interfacing the closed world assumption of NTPs with CRMinf

Starting Date: 
Working Group: 

In the 54th CIDOC CRM & 47th FRBR/LRMoo SIG Meeting, upon discussing the presentation by Thanasis Velios on Typed and Negative Typed Properties, the SIG resolved to start a new issue, where to discuss expressing the idea that an object has been completely observed and has been found to lack a certain feature. This fact forces a closed-world assumption on the object of documentation. 

Rome, September 2022

Post by Martin Doerr (22 November 2022)

Dear All,


I have promised to present some ideas we had discussed in the past in the context of biodiversity, about observation proving that some species is extinct, or in archaeology, about the absence of some phenomenon.

Typical examples are the unnoticed survival of the sea otter  in the Monterey area of California in a small bay, and the so far unique find of gears from whole antiquity in the Antikythera Mechanism - people would not have put such things in graves.

Another example is the lack of fish bones in Minoan culture - they are simply not preserved in the Cretan climate. 

The Negative Typed Property states that the domain has no relation to any instance of the referred type. We can argue, that a reasonable assessment of non-existence should imply:

A) the respective potential instances must have a reasonable likelihood to be preserved to the time of observation at least in traces.

B) the applied method of observation must be suitable to detect them, in particular traces.

C) the domain instance, the one lacking the relation, must be observed with sufficient density and coverage.

C1) In case of species, there are arguments about minimal populations and the areas they would roam about, so that the observation density needs not be complete coverage. Similar arguments may apply to archaeological object types.

The issue second to be discussed is the time of validity.

A) Eternal:

    A1) The domain object under investigation has never had such a relation since its begin of existence. This is a question of temporal coverage, or of proof that traces would still exist, or that that the object had not the possibility until the end of observation. These senses produce a sort of being "current", up to the time of last observation.

    A2) The domain object under investigation has never had such a relation since its begin of existence and will not have until its end, such as putting wheels on a piece of cloth, or putting leaf markers in ancient books in a museum, or in investigating remains of past objects or a past activity/ extinct culture, or the instances of the related type do no more exist.

B) From some time on: The domain object under investigation has lost such a relation. This is characteristic for extinction. The species cannot be recreated. Similarly for any type with instances that do no more exits after the referred time of loss and end of observation.

C) For the period of observation only.

For the time being, we can state that the meaning is always at least C), and there may be arguments for more.

If a negative property held before some time, we have to think more about it.

Probably, a good practice will be to associate an observation with the negative property.


So far my ideas.





Post by Thanasis Velios (24 November 2022)

Thank you for this analysis Martin. I would argue that this is for issue 610 - I have included it in the working document for that issue to discuss.

All the best,


Post by Martin Doerr (30 November 2022)

Dear Thanasis

Yes,it is about Issue 610, but it is also an epistemological background for an interface to CRMinf (Issue 609), where we would need to study how such arguments can be documented.



In the 55th joint meeting of the CIDOC CRM and SO/TC46/SC4/WG9; 48th FRBR/LRMoo SIG meeting, upon discussing issue 610 MD presented 3 competing views on the temporal validity of NTPs –namely their temporal validity interpreted as (i) eternal, (ii) continuous from a point on in time, (iii) continuous in relation to a period of observation –and made the argument in favor of (iii) being the safest option in terms of reasoning. 

Discussion points: 
For interpretation (i): there are cases that one can safely claim for something not being present that it never has been or never will be present (i.e., in a medieval manuscript that had never had leafmarks on it, it would be weird to claim that it is possible to add leafmarks to it in the current age, or at some later stage). 

The analysis by MD is relevant for issue 609 (under which it was originally posted). No effect on implementing NTPs for RDFS. 
Way to move forward: MD, SdS, TV, PF, WS to discuss the temporal validity of NTPs (and overall Ps). Inform 609 with this decision. 


Belval, December 2022 

In the 57th CIDOC CRM & 50th FRBR/LRMoo SIG Meeting, the SIG went through MD’s HW on defining the conditions for an investigation to be considered complete -i.e., one that justifies the lack of observations for a given feature to be considered valid and trustworthy. 

For the details of the proposal and the document drafted by MD, see here.


  • The document that MD drafted will serve as a guideline/comment on the use & meaning of NTPs (to be consulted in combination with Velios et al, 2023). Once it has reached a stable form, it will appear on the CRM website.
  • HW: SdS to proofread the text & link to Velios et al., 2023 
  • HW:  SdS, GH, MD, TV to elaborate the properties needed to express the temporal validity of the lack of observations for a given feature, based on data from archaeology (GH to provide datasets on prehistoric surveys, SdS to provide datasets from archaeological excavations) and conservation (TV to provide them). 

Marseille, October 2023

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