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[I sent out an earlier version of this post over the weekend, but fortunately it had not appeared on the list as of this writing. It serves as a cautionary tale to me not to do this sort of stuff on an iPad (at least not till my skill level has increased).]

This is the second of the Task Group’s questions, previewed in my presentation at OpCo earlier in the month. Thanks to Yang Wang, Kevin Randall, and Jessica Janecki for their thoughtful replies to the first question. Note that discussion of that question remains open and continues to ramify (see Jean Godby's reply to Yang's reply and Yang's recent elaboration, which will in turn elicit a reply).

The second question has multiple aspects, some anticipated in Kevin's reply to the first:

What triggers creation of a Work description in a Linked Data environment?

• What conditions must be satisfied?
• What properties (attributes and relationships) must be included?
• What services require works?

BACKGROUND

There should be clear and consistent guidelines to allow programs and catalogers to definitively determine when the creation of a Work entity is warranted.  While this seems as though it should be straightforward and simple, the concept of a Work tends to be loosely defined and the properties that describe a work vary both across and within communities (e.g., OCLC/schema.org creativeWork vs. BIBFRAME Work vs. FRBR Work).  If PCC were to decide that work entities should not be created for singletons or unique resources, what would be the trigger to create a work entity for resources that have multiple expressions or multiple manifestations of a single expression?

Contributing to the ambiguity surrounding the Work concept are vague definitions and a lack of consistent modeling among standards within and across communities. This ambiguity leads to different interpretations of the triggering event for creating a new Work.  In FRBR, for example, multiple FRBR Expressions may be clustered under one FRBR Work, but the guidelines for triggering a new FRBR Work (i.e. what constitutes a new Work rather than a new Expression) are left to the implementation.  Meanwhile in BIBFRAME, FRBR Work and Expression data are combined such that each new FRBR Expression triggers a new BIBFRAME Work.

Such ambiguity leads to more questions than answers about when to create a new work.

• Do different resource formats require different triggering points for creating a new work entity?  Is the triggering event for creating a new Work the same for serials, music, film, and monographs?  
• Should a separate work entity be created only when there are multiple Expressions? What are the ramifications from cataloging workflow, data modeling, and machine processing perspectives?  Is there any advantage to creating a Work for every Expression?
• Should a Work entity be created if there are only multiple Manifestations of a single Expression?  
• Current cataloging practice expects some descriptive properties of a Work, Expression and Manifestation to be distributed across the WEMI entities.  If Works are created only when there are multiple Expressions or multiple Manifestations, what changes are needed to cataloging rules and modeling assumptions to accommodate ‘Work’ data in a single-entity description model?

At least within the cataloging community, there should to be precise and firm rules regarding the triggering events for creating new Works, even if those triggers vary by format.  Adding clarity to Work description now will not necessarily solve the ambiguities inherent in legacy data but can bring standardization to new cataloging and facilitate future change.

The answer to this question may largely determine the answer to the question of whether Work descriptions can be created by machine, and if so, under what conditions and how autonomously? This question was raised in Yang's latest (May 25) reply. Answering it will have consequences for the extent to which the machine creation of Work descriptions can effect economies in the cataloging process.

Ed Jones,

Chair, PCC SCS/LDAC Task Group on the Work Entity