Error during command authentication.

Related to today’s discussion of the status of EDTF, I am forwarding a message I just sent to NDMSO concerning some examples using EDTF in the MARC formats.  I am happy to see that a first reading of Best Practices for Recording Faceted Chronological Data in Bibliographic Records seems to indicate that it avoids the same pitfalls.  Maybe this will be useful information for some.

 

 

 

The examples on https://www.loc.gov/marc/bibliographic/bd388.html include 046 fields using dates in EDTF.

 

046	##$k07uu/1100$2edtf
245	00$aBeowulf
388	1#$aAnglo-Saxon period$2[source code for controlled vocabulary] [A work originally written between the 8th and 11th centuries A.D.]
046	##$o-07uu/-05uu$p06uu$2edtf
245	00$aBroken laughter :$bselect fragments of Greek comedy.
388	1#$aAncient period$2[source code for controlled vocabulary] [An aggregation of ancient Greek fragments, the dates of which could range from the 8th-6th centuries B.C. to the 7th century A.D.]

 

The final version of EDTF released last year (https://www.loc.gov/standards/datetime/) replaced the use of “u” for unspecified digits with “X”.  However, the examples cannot be corrected by a simple substitution.  The use of a slash between dates indicates a time interval.  A time interval is defined in ISO 8601-1:2019 as “part of the time axis (3.1.1.4) limited by two instants (3.1.1.3) and, unless otherwise stated, the limiting instants themselves.”  That’s kind of technical, but ISO 8601:2004 included the note “A time interval comprises all instants between the two limiting instants and, unless otherwise stated, the limiting instants themselves.”  In other words, a time interval is the entire span of time between the start point and the end point.  It should not be used for something that happened at some point in time during that interval.  The time of creation of Beowulf is very much uncertain, but no one claims it was a process of continual creation from the 8th to the 11th century.  ISO 8601 and EDTF don’t really have a way of identifying such vague concepts, so it doesn’t make sense to try to express them in field 046.  Such concepts are better expressed in word phrases such as are used in field 388. 

 

The second example, which gives an interval as the “single or starting date for aggregated content,” is even more problematic. Again, this kind of date cannot be reduced to coded form in 046; it is best given in text in field 388.

 

The next example on the 388 page is

 

046	##$k1985$l9999$o1801$p1899
245	00$aNineteenth century English drama$h[microform]
388	1#$a19th century$2[source code for controlled vocabulary]
388	2#$a20th century$a21st century$2[source code for controlled vocabulary] [A set of English drama originally created from 1800-1899 and aggregated in a microform set beginning in 1985]

 

There is a similar example on the page for 046 (https://www.loc.gov/marc/bibliographic/bd046.html)

$o - Single or starting date for aggregated content

Single or starting date of original release of the contents of a collection/aggregation.

008/06-14	m19859999
046	##$o1800$p1899 [A set of English drama originally created 1800-1899 and published as a microform set beginning in 1985]

 

The examples seem to be describing the same thing, but they use different values in 046 $o.  However, it is false precision to use such exact dates to represent a collection of 19th century drama.  If one investigated the dates of creation of each part of the collection, one could use the earliest and latest dates in 046 $o and $p.  Otherwise, it is sufficient and more representative to use 046 $o 18 (without $p).