[tdwg-content] New Term needs resolution: DigitalStillImage

[John Wieczorek]

Darwin Core Issue 68: http://goo.gl/Q7TRn

This term has undergone extensive public commentary since January 2010
when it was first proposed. I will do my best to summarize the
thinking on these issues, but please see the full corpus of
discussions on tdwg-content to see the full history.

It has been suggested that DigitalStillImage is not necessary as a
Darwin Core Type vocabulary term (one of the controlled vocabulary
terms for basisOfRecord) for at least two reasons:

1) Dublic Core comments on StillImage
(http://dublincore.org/documents/dcmi-type-vocabulary/) as: "Note that
Image may include both electronic and physical representations."

2) The basisOfRecord term has no real purpose and without it, there
was no need for DigitalStillImage as one of its controlled values.

The context for the second statement was the use of Darwin Core in
RDF. The basisOfRecord term is essential in data sharing mechanisms
such as in Simple Darwin Core text files or Darwin Core Archives where
there is no other way to express what is the fundamental concept for a
record.

The impetus for proposing DigitalStillImage was to allow the
basisOfRecord to show that the evidence for an Occurrence was based on
a digital image (similar to a PreservedSpecimen being evidence). This
purpose still has merit.

Discussions on DigitalStillImage touched on many other issues related
to ontology and missing or inferred Classes in the Darwin Core. To
achieve the original goal behind DigitalStillImage for RDF is more
complicated and involves the idea of a Class to represent a concept
that could be described as "Evidence". I will create a separate thread
for the continuation of that discussion, reserving this thread for the
closure of the issue of having no way currently to express that a
digital image is the basis for a Darwin Core resource.

To achieve the original goal for the case of non-RDF data sharing
mechanisms, I propose that StillImage be added to the list of
recommendations for the Darwin Core Type Vocabulary, along with
MovingImage and Sound. Doing so will create no backward
incompatibilities in the Darwin Core.