Content-oriented Criteria

Content-oriented Criteria

The following criteria have been selected to verify whether or not the ‘digital library’ conforms to the Digital Library Reference Model from the Content domain point of view.

MANDATORY
Regardless of the type of Content a ‘digital library’ was conceived to hold, it must meet at least the following criteria:
» The Digital Library must manage a set of Information Objects and the set cannot be empty.
By definition the purpose of a digital library is to collect, manage and preserve in perpetuity digital content.
» Every Information Object must have (identifiedBy) a unique identifier (Resource Identifier).
This guarantees that each Information Object managed by the ‘digital library’ is distinguishable from the remaining ones in the context of the same ‘digital library’.
» Every Information Object must have at least one element of Metadata (hasMetadata) associated with it.
This ensures that each Information Object is equipped with data supporting its management and use.
»    Every Information Object must belong (belongTo) to at least one Collection.
This guarantees that the overall set of Information Objects managed by the ‘digital library’ pertains to an organized body.
»    Every Collection must have (identifiedBy) a unique identifier (Resource Identifier).
This establishes that each Collection managed by the Digital Library is distinguishable from any others in the context of the same Digital Library.
»    Every Collection must have at least one element of Metadata (hasMetadata) associated with it.
This asserts that each Collection is equipped with data supporting its management and use.

RECOMMENDED
Additional desired properties of a ‘digital library’ are:

• Every Information Object should conform to (hasFormat) an explicit and known format (Resource Format).

This guarantees that the system is aware of the “structure” each Information Object conforms to and that this structure is publicly declared thus making the Information Object usable by third party actors whether human or machine. The notion of Resource Format is wide and might range from an abstract one (e.g. “enhanced publication”) to a concrete one (e.g. PDF).

• Every Metadata should conform to (hasFormat) an explicit and known format (Resource Format).

This criterion – a specialization of the previous one – ensures that the system is aware of the “structure” the metadata object conforms to and that this structure is publicly declared so that it can be used by third party actors whether human or machine. In this case the notion of Resource Format corresponds to the notion of metadata schema.

• Every Annotation should conform to (hasFormat) an explicit and known format (Resource Format).

This criterion guarantees that the system is aware of the particular “structure” to which the annotation object conforms. Being publicly declared, this structure can be used by third party actors whether human or machine.

• Every Collection should have a well-defined intension, i.e., the set of criteria characterising Collection membership (hasIntension), and should have a well-defined extension, i.e., the set of Information Objects belonging to the collection (hasExtension).

The collection concept is fundamental to keep the set of Information Objects organised. Because of this, it is recommended that both the set of Information Objects belonging to a collection and the criteria driving the membership of an information object into a collection are clearly defined.

• Every Information Object should be regulated (regulatedBy) by Policies.

Policies are essential to establish conditions, rules, terms or regulations governing the management of information objects.

OPTIONAL
Finally, a ‘digital library’ may also meet the following set of criteria:

• An Information Object may have multiple Editions (hasEdition) each represented by a different related Information Object.

• A ‘digital library’ might be employed to manage multiple editions of the same work. In these cases it is important to deal effectively with the edition concept.

• An Information Object may have multiple Views (hasView) each represented by a different related Information Object.

• A ‘digital library’ might be called to manage multiple “views”/“expressions” of the same conceptual work. In these cases it is important to properly deal with the view concept.

• An Information Object may have multiple Manifestations (hasManifestation) each represented by a different related Information Object.

• A ‘digital library’ might be called to manage multiple “items” of the same conceptual work or view. In these cases it is important to properly deal with the manifestation concept.

• An Information Object may be compound (hasPart), i.e., it may consist of multiple Information Objects.

• Modern ‘digital libraries’ are usually expected to deal with emerging forms of “documents”. Very often such a “documents” consists of aggregates of other objects (of different media).

• An Information Object may be associated (associatedWith) with other Information Objects for a certain Purpose.

• Managing compound objects may require links other objects. The motivations leading to linking are diverse and context specific, e.g., citation and lineage.

• An Information Object may have multiple elements of Metadata (hasMetadata) associated with it.

• Metadata are a type of Information Object intended to support the management and use of the Information Objects to which they are attached. Different metadata can be conceived to support diverse needs. The majority of ‘digital libraries’ tend to deal with a single metadata format.

• An Information Object may be associated with multiple Annotations (hasAnnotation).

• Annotations are kinds of Information Objects that are attached to existing Information Objects for various purposes including objects enrichment and cooperative working.

• A Collection may be associated with multiple Metadata (hasMetadata).

• According to the Reference Model, Collections are a type of Information Object. Because of this, they inherit all the features of Information Objects and benefit of multiple metadata.
• A Collections may be associated with multiple Annotations (hasAnnotation).

• According to the Reference Model, Collections are a type of Information Object. Because of this, they inherit all the features of Information Objects and benefits of multiple annotations.