On 3 Aug 2023, at 19:49, Wesley M. Hochachka <wmh6@cornell.edu> wrote:

Hi Ming,

   If I am correctly understanding the use of eco:isAbsenceReported, then the value of eco:isAbsenceReported should be irrelevant to whether eco:isTaxonomicScopeFullyReported is set to be "true" or "false".  I am assuming thateco:isAbsenceReported and eco:isTaxonomicScopeFullyReported are independent of each other, such that all four combinations of conditions can occur:

1. eco:isAbsenceReported = false and eco:isTaxonomicScopeFullyReported = false: in this case the absence of the report of a taxon within the taxonomic scope cannot be interpreted.
2. eco:isAbsenceReported = true and eco:isTaxonomicScopeFullyReported = false: in this case the absence of the report of a taxon within the taxonomic scope cannot be interpreted, because the combination of these two conditions says that "some counts of zero are being reported, but not necessarily for all of the species within or outside of the taxonomic scope.
3. eco:isAbsenceReported = false and eco:isTaxonomicScopeFullyReported = true: in this case the absence of the report of a taxon within the taxonomic scope can be interpreted to mean that the species was not detected, but these non-detections will need to be inferred because they are not explicitly entered as records of counts of zero.
4. eco:isAbsenceReported = true and eco:isTaxonomicScopeFullyReported = true: in this case, the absence of the report of a taxon within the taxonomic scope can be interpreted to mean that the species was not detected, and there is no need to infer these absences because counts of zero will be present for all taxa that were not detected.

Again, what I have written above is based on the assumption that I fully understand the use of eco:isAbsenceReported.  If this assumption is wrong, then I think that the definition should be tweaked to make its interpretation unambiguous, because my interpretation is consistent with the definition, as far as I can tell.

   I do not think that there is any way to differentiate between a sampling event in which only by-catch was detected but it was not reported, and a sampling even detected literally no organisms of any taxon (within the constraints of the sampling methods).

   From an ecological perspective, the distinction could be important, because the two extreme alternatives are the difference between "our target taxa were not detected but there were still organisms (i.e. the by-catch) detected", and "the sampling area was devoid of detected life".  So, these extreme alternatives could only be differentiated of at least one by-catch taxon was reported for the sampling event.  However, this feels somewhat dis-satisfying to me, because it's still not possible to tell the difference between "none of the target taxa were detected and just a single organism of any taxon was detected", and "lots of different non-target taxa were detected, but we only bothered to report one of them".

   Reports of by-catch (which I'd generically call "presence-only data") is just massively limited in its interpretability.

   So, anyway, those are my answers to your questions.  You might want to forward my reply on to the Humboldt Extension listserv, because it's almost certain that my attempt to send my reply to this listserv is going to fail.

Wesley

*******************
Wesley Hochachka
Senior Research Associate
Cornell Lab of Ornithology
ph. (607) 254-2484
*******************

---

From: Yi Ming Gan <ymgan@naturalsciences.be>
Sent: Thursday, August 3, 2023 06:10
To: tdwg-humboldt@lists.tdwg.org <tdwg-humboldt@lists.tdwg.org>; Rob Stevenson <rdstevenson10@gmail.com>
Cc: Wesley M. Hochachka <wmh6@cornell.edu>
Subject: How to populate/interpret eco:isTaxonomicScopeFullyReported if dwc:Event caught nothing/something outside of eco:targetTaxonomicScope?

 

Hi all,

In my attempt to use Humboldt Extension to infer non-detection, I arrived at this question because it is not clear to me how to use null in the following situation.

Should eco:isTaxonomicScopeFullyReported (previously eco:isTaxonomicScopeComplete) be "true", "false" or null if an dwc:Event do not catch anything within the eco:targetTaxonomicScope and eco:isAbsenceReported == "false"?

I illustrate my understanding in the table below:

• assume that all the catch are reported in the Occurrence extension

eventID	catch	eventRemarks	targetTaxonomicScope (taxa are pipe-separated)	isAbsenceReported	isTaxonomicScopeFullyReported	can infer non-detection of taxa within targetTaxonomicScope?
event_001	A		A | B	false	true	true
event_002	A		A | B	false	false	false
event_003	A, C		A | B	false	true	true
event_004		by-catch only	A | B	false	true	true
event_005		by-catch only	A | B	false	false	false
event_006		by-catch only	A | B	false		false
event_007		caught nothing	A | B	false	true	true
event_008		caught nothing	A | B	false	false	false
event_009		caught nothing	A | B	false		false

How can I distinguish:

• an dwc:Event caught by-catch only, but did not report it (no dwc:Occurrence record associates with the dwc:Event)
  
• an dwc:Event caught nothing at all

Is this distinction important? Can someone with ecology or relevant background please comment? @Rob Stevensonmaybe? 

Thanks a lot!

Cheers

Ming