Linked data and URIs -- #3 Data Provenance Subfields

Data provenance subfields ($0 and $1) provide information about metadata/cataloging data in other subfields within the same MARC field.

Codes in parentheses at the beginning of these subfields refer to the category of information given and the subfield within the MARC field to which they apply (if they don’t apply to all of the subfields). The meaning of these codes is given in MARC documentation (Ex. https://www.oclc.org/bibformats/en/controlsubfields.html#subfielddp))

We’ve always provided information about our metadata within catalog records, but these subfields allow us to provide this information in a more structured way than we have in the past.

For example, here’s the same note without and with information about the source/ provenance of the cataloging data given in a separate subfield. The code in parentheses tells you that the text in the subfield $7 is a “note on metadata work,” i.e. a note about the cataloging data. In this example, there’s no need to also include an indication of the subfield to which this text applies because there’s only one other subfield in the 520 field:

520__”Everybody has needs. This nonfiction book explores the basic needs of people and how we get our needs met”—Publisher’s website.

520__”Everybody has needs. This nonfiction book explores the basic needs of people and how we get our needs met”$7(dpenmw)Publisher’s website.

Here’s an example with the source consulted for the metadata in the 264 subfield $a given in both textual and URI forms in separate subfield $7s. The first code in parentheses tells you that the category of information provided about the metadata is “source consulted” and the second code tells you that the information applies to the subfield “a” of the 264 field:

264 #1 [Helsinki] : $b Dionysos Films, $c [2019] $7 (dpesc/dpsfa)Dionysos Films website $7 (dpesc/dpsfa)https://www.dionysosfilms.fi/

Subfield $0 vs. Subfield $1

As explained in the last post, subfield $0 carries the “Authority record control number or standard number.” A URI used in $0 will link to a description of the name or label used in the MARC field. The subfield $1 carries a “Real World Object (RWO) URI,” linking to a description of an entity.

The descriptions that these two types of URIs link to might look identical at first glance. So, what’s the difference?

Remember that the purpose of linked data is to make it easier for computers to find and interpret information. In linked data world, it’s important for computers to be able to distinguish between a name used for an entity and the entity that’s being named. The subfields used for URIs signal this distinction. URIs entered in subfield $0 link to authority records for names or terms used for entities (people, places, corporate bodies, etc.), while Real World Object (RWO) URIs entered in subfield $1 link to descriptions of the entities themselves (the actual people, places, corporate bodies, etc. behind these names or terms). My personal mnemonic device for this is that “0” comes before “1,” and we had authority records in the library world long before records for “real world objects.”

For example, a URI in the subfield $0 of a 100 field for the author Charles Dickens would refer to his name, the alphanumeric string that is used to identify him (Dickens, Charles, $d 1812-1870), while a URI entered in a subfield $1 of the 100 field for this author would refer to the human being who wrote “Bleak house” and is identified by this name.

Even though they might appear similar at first glance, records linked to by URIs in subfields $0 or $1 may contain different types of data. In the next few posts, we’ll look at an example of three types of links in a catalog record with URIs that link to three different types of descriptions.

This is the third in a series of seven weekly blog posts written by Zahra Gordon, the NHSL Cataloger, which will explain “Linked Data,” an emerging topic in the library field, and how it relates to “Uniform Resource Identifiers (URIs),” which are appearing in subfields of MARC records with increasing frequency.