Authority Control
The LTI Difference, pt. 2
Serving Two Masters
By definition authority control demands a single "authority." If the library's local system has its own "authority module" that flips headings based on 4XX fields in authority records, one is inviting Chaos to rule supreme over headings. On a regular basis LTI users report strange things when they "turn on" their ILS authority control module. A primitive authority control module, even when it was offered as "free" or at a greatly reduced price, is no bargain and will result in corrupted headings.
As with errors introduced by second-rate authority control vendors, detecting corrupted headings triggered by the library's local system is serendipitous. For example the library may come across an inordinate number of headings tagged as subjects but that are in fact uniform titles or series. While a series may on rare occasions be used as a subject, it is most uncommon, and it is never permissible along with the presence of form ($v), topical ($x), period ($y), or geographic ($z) subdivisions. Examples of mangled headings in topical subject [650 fields] caused by the library's authority module are listed below.
$aAmerican university studies.$nSeries II,$pRomance languages$xGrammar, Comparative$xRomanian.
$aAmerican university studies.$nSeries II,$pRomance languages$xModality.
When one examines the authority record for "American university studies. Series II. Romance languages," one finds a 430 x-reference for "Romance languages." Pretty clearly at one time the LCSH heading was "Romance languages," but a simplistic automated routine "flipped" that LCSH heading to the series title "$aAmerican university studies.$nSeries II,$pRomance languages". LTI's processing protects against this type of incorrect tag level change and, if not linked correctly by our code or editors, at worst the above headings appear in the unlinked headings list.
Such problems appear to be present in all databases where the library uses an authority control module made available by its ILS vendor. Mangled headings are not limited to any particular ILS. Regardless of local system, LTI strongly advises that ILS automatic changes to catalog record headings based on authority records be disabled. The library has paid for and received the best authority control available to libraries today. Superimposing a redundant level of ILS "authority control" serves only to undermine the advanced algorithms and tables that were used to authorize the library's database.
The culprit is that local system authority control modules rely on the presence of the "old" heading as a 4XX field in an authority record. Not only does LC frequently not carry over the "old" heading, even if it did there may be other issues in linking the "old" heading because of variations in capitalization, spacing, or punctuation occurring, in either catalog record headings or in LC authority records. We see and report dozens of such errors in LC records each week.
As illustrated in the cited examples, there are many instances in which a link should not be made. While LTI processing results in the highest link rate of any authority control vendor, avoiding bad links demands even more vigilance. Presently, we block over 163,000 headings in authority records (mostly 4XX fields) from linking to any catalog record heading because of the likelihood of introducing an error in a library's file. Other heading changes are limited to only certain types of linkages-i.e., there must be additional data present before the link is allowed. Software that allows wholesale revisions of 650 subject headings based on a 430 in a series authority record is not something a library wants to be in control of its headings.
LTI's substantially more refined and tested routines not only prevent bad changes from occurring, they also make thousands of needed revisions that are not possible with a simple routine that flips headings if a 4XX field with matching text is found in any authority record. Internal studies have shown that reliance on the LC record alone misses one-half to two-thirds of the needed changes. In short, when judiciously used, your library's ILS authority control module is perhaps better than none at all, but is certainly no replacement for a comprehensive batch and continuing authorization service.