“In the FRBR-LRM model, the relationships are declared in a general, abstract way and thus enable implementers to include additional details in a consistent and coherent way by introducing additional types….” “The relationships between works, expressions, manifestations, items are the core of the model and can be considered mandatory. Other relationships are encouraged, since they enable exploration and discovery and are very important for users.” p. 43


Res and Nomen

One of the higher level entities is “nomen” which was first seen in FRSAD. The term means “name” in Latin (there’s nothing friendlier to a modern audience than using Latin terms!). Nomen is s subclass of “Res” (Latin for “thing”). Here’s how they are defined:

Res includes both material or physical things and conceptual objects. Everything considered relevant to the bibliographic universe, the universe of discourse in this case, is included. Res is a superclass of all the other entities that are explicitly defined, as well as of any other entities not specifically labeled.”

If you have experience with OWL you will recognize that Res is very similar to owl:Thing, which is defined: “Every individual in the OWL world is a member of the class owl:Thing. Thus each user-defined class is implicitly a subclass of owl:Thing.” owl:Thing also includes physical and conceptual objects; in fact, it includes everything that is not owl:Nothing.

Nomen, is an entity at the same logical level as Work, Expression, etc., and Person. All are subclasses of Res. Nomen is defined as “Whatever appellation is used to refer to any entity found in the bibliographic universe.” Then it goes on to say:

“Depending on the context of use, the same sequence of symbols can be assigned as a nomen of different entities in the real world even within the same language (polysemy and homonymy). Conversely, the same entity can be referred to by any number of nomens (synonymy). The association of nomens to entities is in general many-to-many.” (p. 20)

We recognize this as the ambiguity of natural language that humans navigate rather well in real life, but that causes us great problems when we need greater precision. Because machines do not have the intelligence to work within the complex information context that humans occupy, we resort to the creation of unambiguous identifiers to solve the precision problem.

However, FRBR-LRM considers identifiers to also be nomen, and this is in contradiction to to the concept of and use of identifiers in any community that I have encountered. By considering that identifiers, as nomens, can be many-to-many the LRM eliminates any notion of unique identification, making functioning with data to be essentially logically impossible. As examples of identifiers as nomen they use an ISBN and an ISNI. Here’s what says about the role of its identifiers:

“The mission of the ISNI International Authority (ISNI-IA) is to assign to the public name(s) of a researcher, inventor, writer, artist, performer, publisher, etc. a persistent unique identifying number in order to resolve the problem of name ambiguity in search and discovery…” (emphasis in original)

“Unique” – that’s the key. Identifiers are identifiers because they are unique. Mixing unique identifiers and non-unique names in a single entity ignores the vital importance of identifiers. Names can vary; you can have full names, short names, nicknames, terms in various languages – all of those are names and we accept that, while they communicate to human beings are do not carry the precision needed for data processing. Identifiers must identify, something that names do not do. Names and identifiers are not the same thing. Period.

Oh, and the irony is that they have assigned unique identifiers to the LRM entities. Why? “Every element in the model is numbered for unambiguous reference.” (p.11)


Definition of person/pseudonyms

“The entity person is restricted to real persons who live or are assumed to
have lived.” p. 19

This definition has been noted in some email discussions.(See below) By limiting the entity Person to real life beings questions come up to how pseudonyms and fictional persons will be handled. Dunsire‘s reply is that a single identifier will be used with display labels for the various personas of the natural person. It is fairly easy to come up with situations in which that may not work (e.g. more than one person for a persona). It also isn’t clear how the various personas will be clearly associated with individual works.

Email discussions:

RDA-L – Weisenmuller – Reply: Dunsire

RDA-L – Maxwell

5.5 Modelling of Aggregates

“An aggregate is defined as a manifestation embodying multiple distinct expressions. Three distinct types of aggregates exist:”

  1. Aggregate Collections of Expressions

  2. Aggregates Resulting from Augmentation

  3. Aggregates of Parallel Expressions

p. 64-66

5.4 Representative Expressions

“In a strict formal sense, within the model all the expressions of a work are equal as realizations of the work. However, research with users indicates that they recognize that works have original or “canonical” expressions, those that can be said to best represent the initial intention of the creators of that work. Other expressions can, if the full history of the work is known, be seen as taking shape from a network of derivations or transformations starting from this original expression.” p. 62

5.3 Modelling of Bibliographic Identities

“The modelling of bibliographic identities or personas in FRBR-LRM makes use of the nomen entity and the has appellation relationship. The appellation relationship is one-to-many and holds between any entity and the various nomens used for that entity. In particular, persons (defined as: an individual human being) generally have multiple nomens; the use of each nomen may be governed by many factors, including the preference for certain nomens in specific contexts.” p. 61

5. Attributes

Here is a brief outline of the entities and attributes, first the entity, with the attributes below it:

  • Res
    • Category
    • Note
  • Work
    • Category
  • Expression
    • Category
    • Representivity
    • Extent
    • Intended audience
    • Rights
    • Language
    • Key (music)
    • Medium of performance
    • Scale (cartographic)
  • Manifestation
    • Category of carrier
    • Extent
    • Intended audience
    • Manifestation statement
    • Access conditions
    • Rights
  • Item
    • Location
    • Rights
  • Agent
    • Contact information
    • Field of activity
    • Language
  • Person
    • Profession/occupation
  • Collective agent (no attributes)
  • Nomen
    • Category
    • Scheme
    • Intended audience
    • Context of use
    • Reference source
    • Language
    • Script
    • Script conversion
    • Status
  • Place
    • Category
    • Location
  • Time-span
    • Beginning
    • Ending