[tdwg-content] Conflict between DarwinCore and DublinCore usageof dcterms:type / basisOfRecord

Steve Baskauf steve.baskauf at vanderbilt.edu
Sun Nov 1 13:29:27 CET 2009

I hesitated to respond to this earlier because I am not up on what is 
going on in the "observation" community of tdwg and how they define 
things.  However, I have a philosophical problem with saying that 
HumanObservations and MachineObservations should be typed as 
dcterm:type=dcmitype:Event.  My problem stems from the way that we use 
"observation" in English. 

1. When a taxonomist conducts a field collecting trip (a dcterm:event) 
at a certain time and place, we end up with a specimen 
(dcterm:type=dcmitype:PhysicalObject, dwc:basisOfRecord="PhysicalSpecimen").
2. When a photographer conducts a photo shoot (a dcterm:event) at a 
certain time and place, we end up with a still image 
(dcterm:type=dcmitype:StillImage, dwc:basisOfRecord="StillImage").
3. When a birdwatcher conducts an observation (a dcterm:event) at a 
certain time and place, we end up with an observation (dcterm:type=???, 

In example 3, the problem is that we use the same word ("Observation") 
for the act of observing and the product that we create when we 
observe.  We don't do this for other types of things that belong in the 
dwc:recordClass = dwctype:Occurrence (i.e. examples 1 and 2).  If you 
look at the elements in the DwC class Occurrence, you see elements that 
can describe the things that are created when we document the presence 
of an individual, e.g. catalogNumber, preparations, sex, etc.  If you 
look at the elements in the Dwc class Event, you see elements related to 
the act of creating, e.g. the time (eventDate), place (habitat), and 
method (samplingProtocol).  The use of the word Event to describe a DwC 
class is true to the DCMI definition of Event: "Metadata for an event 
provides descriptive information that is the basis for discovery of the 
purpose, location, duration, and responsible agents associated with an 
event. Examples include an exhibition, webcast, conference, workshop, 
open day, performance, battle, trial, wedding, tea party, 
conflagration."  The examples given in the definition all indicate 
things that happen, not the things that result from those happenings 
(i.e. exhibitions, not exhibits; conference, not proceedings; battle, 
not dead people; tea party, not tea; etc.).

As I look at the DCMI classes, the problem is that I don't think there 
is one that describes observation (in the sense of an Occurrence, i.e. 
the product that is created when we observe).  So I think that the 
appropriate thing in the case of observation is either to provide no 
value for dcterm:type or to petition DCMI to create a class for 
observations (if we can get them to understand the distinction that I'm 
making between act and product).  I do not think that the appropriate 
thing is to call observations (sensu created product) something that 
they are not.  I have previously raised the question of "Why do we need 
dcterms:type?".  I do not think that the reason is to satisfy our need 
to place all things into conceptual boxes.  I think the reason is to let 
a machine or user know what kinds of metadata to expect when they are 
told that a record has a particular value for dcterms:type.  Under that 
rationale, if a record identifier is for an observation is being 
resolved and a consuming application is told that the record has a 
dcterm:type of Event, that application is going to be expecting metadata 
about an act (time, place, and method), not metadata about a created 
entity (catalog number, sex, or whatever types of things that you record 
about an observation).  It is better to tell the machine nothing than to 
tell it to expect the wrong thing.  While it is true that observations 
have a time, place, and method of creation, PhysicalObjects and 
StillImages also have a time, place, and method of their creation, yet 
we do not class them as Events.  Let's not put a round peg into a square 
hole.  Either leave the peg out or drill a round hole.

Steve Baskauf

John R. WIECZOREK wrote:
> Found a moment to get back to this. There currently is no formal (that
> is, rdf) relation between observations and dcmitype:Event. In fact,
> there are no formal relations between recommended basisOfRecord values
> ("PreservedSpecimen", "StillImage", "HumanObservation") and any
> dcmitype terms (dcmitype:PhysicalObject, dcmitype:StillImage,
> dcmitype:Event). The former are string literals in a list that is
> recommended while the latter are the DC recommended Type Vocabulary
> for dcterms:type.
> So, if I was to publish a record for a human observation of a species
> in nature (a dwc:Occurrence), I would populate the terms as follow
> (note specifically the use of terms for type and recordClass and the
> use of a string for basisOfRecord):
> dcterms:type = dcmitype:Event
> dwc:basisOfRecord = "HumanObservation"
> dwc:recordClass = dwctype:Occurrence
> For your other example I would populate the terms similarly, with:
> dcterms:type = dcmitype:Event
> dwc:basisOfRecord = "MachineObservation"
> dwc:recordClass = dwctype:Occurrence

Steven J. Baskauf, Ph.D., Senior Lecturer
Vanderbilt University Dept. of Biological Sciences

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