Intellectual entity could be the same as the representation or it may not
be, depending upon what objects you have. An intellectual entity may
indeed be represented by a descriptive metadata record (e.g. bibliographic
record in a library catalog) and may be referenced by any kind of unique
identifier. (Institutions could decide which identifier; we might be
inclined at LC to use the LCCN, since that is a globally know unique
the introductory section of the PREMIS report in section 1 about the data
model. See the excerpt below, which describes representations and gives an
example of the distinction between intellectual entity and representation.

The case of a captured website is complicated of course, because there are
so many relationships involved-- there are the embedded files/bitstreams,
like images, flash, etc. that may be embedded or linked to from an HTML
page. So in that case a representation would be all the files needed to
render the page that represents a capture at a particular time. A
repository would not want to give descriptive metadata for each capture of
a website at a different point in time, so the intellectual entity would
be the abstraction of the website, and the representations could be all
the files making up a particular capture. But for simpler types of objects
the intellectual entity and the representation could be the same.

Probably more than you wanted to know, but here is the excerpt from the
PREMIS report:


The goal of many preservation repositories is to maintain usable versions
of intellectual entities over time. For an intellectual entity to be
displayed, played, or otherwise made useable to a human, all of the files
making up at least one version of that intellectual entity must be
identified, stored, and maintained so that they can be assembled and
rendered to a user at any given point. A representation is the set of
files required to do this.

PREMIS chose the term "representation" to avoid the term "manifestation"
as it is used in the _Functional Requirements for Bibliographic Records
(FRBR)_. In FRBR a manifestation entity is "all the physical objects that
bear the same characteristics in respect to both intellectual content and
physical form". In the PREMIS model a representation is a single digital
instance of an intellectual entity held in a preservation repository.

A preservation repository might hold more than one representation for the
same intellectual entity. For example, the repository might acquire a
single image (say, "Statue of a horse") as a TIFF file. At some point the
repository creates a derivative JPEG2000 file from the TIFF and keeps both
files. Each of these files would constitute a representation of .Statue of
a horse.. In a more complicated example, .Statue of a horse. might be a
part of an article consisting of that TIFF image and a file of
SGML-encoded text. If the repository created a JPEG2000 version of the
TIFF, it would hold two representations of the article: the TIFF and the
SGML files would make up one representation, while the JPEG2000 and the
SGML files would make up another representation. How those representations
are stored is implementation specific. A repository might chose to store a
single copy of the SGML file, which would then be shared between
representations. Alternately, the repository could choose to duplicate the
SGML file and store two identical copies of it. The two representations
would then consist of the TIFF and SGML copy 1, and the JPEG2000 and SGML
copy 2.

Not all preservation repositories will be concerned with
representations. A repository might, for example, preserve file objects
only and rely on external agents to assemble these objects into usable
representations. If the repository does not manage representations, it
does not need to record metadata about them.

Intellectual Entities and Objects

The relationship between Intellectual Entities and Objects can be
illustrated by a couple of examples:

Example 1, Animal Antics: The book Animal Antics was published in 1902. A
library digitized Animal Antics, creating one TIFF file for each of 189
pages. As structural metadata, it created an XML file showing how the
images are assembled into a complete book. The library then performed OCR
on the TIFF images, ultimately creating a single large text file that was
marked up by hand in SGML. The library submitted 189 TIFF files, one XML
file, and one SGML file to a preservation repository. 

To the repository Animal Antics is an Intellectual Entity: it is a
reasonable unit that can be described as a whole, with properties such as
an author, a title, and a publication date. The repository has two
representations, one consisting of 189 TIFF files and an XML file, and the
other consisting of one SGML file. Each representation could render a
complete version of Animal Antics, albeit with different functionalities.
The repository will record metadata about two representation objects and
191 file objects.

(then there's a diagram in the report)


On Thu, 6 Jul 2006, Barbara Sierman wrote:

> Hello all,
> We had also problems with the understanding of the
> linkingIntellectualEntityIdentifier;
> - on the level of file, we understood it concerned the linking of
> several digital objects, but this is in our opinion information you
> describe with bibliographic metadata and especially meant for the
> end-user and so you will describe this link at representation level
> - on the level of representation a example was given for website, to
> link the different files together and so create a new Intellectual
> Entity. But this depends on the way you store your different files of
> the websites, they might be stored together in one AIP and so together
> form the Intellectual Entity.
> Kind regards
> Barbara Sierman
> Digital Preservation Officer
> Koninklijke Bibliotheek
> PO Box 90407
> 2509 LK Den Haag
> +31 70 3140109
> [log in to unmask]
> -----Oorspronkelijk bericht-----
> Van: PREMIS Implementors Group Forum [mailto:[log in to unmask]] Namens Zhiwu
> Xie
> Verzonden: woensdag 28 juni 2006 22:33
> Aan: [log in to unmask]
> Onderwerp: [PIG] linkingIntellectualEntityIdentifier
> Hello,
> A question on the use of the linkingIntellectualEntityIdentifier:
> Does the Intellectual Entity an abstraction of the articles, books, etc,
> that the same Intellectual Entity will have multiple representations
> such as one digital object in my repository, another one in your repo,
> and one hard copy in a journal residing on the basement of the science
> library on campus?
> If this is the case, the value of the
> linkingIntellectualEntityIdentifierValue shall be something like a DOI
> number, an ISBN number or alike, instead of an object identifier in some
> repo since that's the ID of just a digital object but not the
> abstraction of that digital object, am I right?
> If this is the case, the usage notes on p.2-70 confuses me:
> "... This may be a link to descriptive metadata that describes the
> Intellectual Entity or some other surrogate for it that can be
> referenced..."
> I had thought the identifer is for the abstract intellectual entity but
> not one of its representation, such as the descriptive metadata. Also:
> "This link will likely be to an identifier of an object that is at a
> higher conceptual level than the object for which the metadata is
> provided, for example, to a collection or parent object."
> Again here the identifier may be for a concrete digital object.
> If this is to link two concrete object, isn't it better to just describe
> it in the "relationship"?
> Also, is there a way to describe the nature of the link, e.g., this link
> is from a MODS metadata object to the intellectual entity, that link is
> from a full-text pdf representation to the intellectual entity? Is there
> a way to convey the descriptive metadata and/or the full-text nature of
> the link?
> Thanks,
> Zhiwu Xie