I am such a cataloging nerd that I am checking the cross references in the catalog to make sure that all of the genre/form headings from LC are in the authorities database. Actually, I think this will help patrons when they are looking for materials of a certain type. The headings I've checked and added as necessary so far are types of: Cartographic materials such as Globes and Relief maps, and for Law materials such as Statutes and codes and Law for laypersons. There approximately fifty individual types of law materials and about a dozen cartographic materials headings.
The next group I will tackle is a big one--Motion pictures. I have many of those, e.g. Science fiction films and Comedy films, already in the authority file, but will be double checking to make sure all legitimate references are in the file. There are approximately one-hundred different film genres listed in the LC Authorities database.

Nowadays most library automation systems use keyword searching for all types of searches, Whether searching for titles, authors or subject headings, the results displayed are those which have the words the user searches on in the particular field they have chosen to search. (The default for most catalogs being a general keyword search, of course, one does have to select a particular type of field to the get specific results for that field, something librarians need to continually stress to their patrons.)
One result of this is that the older lists of titles, authors, subjects, etc. which used to present themselves as the initial search result, are no longer so obvious to the patron. In the Follett Destiny catalog, for example, the patron needs to click on a very small link which asks "Browse subjects?" to get to that list. My guess is that most patrons don't know what that means or bother to find out. One more opportunity to educate when we get the chance.
Because of this keyword default in searching any field, one thing I've begun doing in my cataloging practice to to put multiple subject headings where one used to do. Here's an example: instead of Sports--History--Great Britain, I make two headings: Sports--Great Britain and Sports--History. If the patron searches using the terms "great britain history sports" or "sports history" or "history sports" or any of a number of other combinations this title will appear in the results list. In the past with a strict alphabetical listing of subject headings it wouldn't have been as easy to get this item in the results list except through a full keyword search. I definitely like the new keyword searching capabilities of the catalog but it can also create traps. More on that next time.

Music

Image via WikipediaMusic is great fun to catalog if you're not a musician. I'm being sarcastic.
Recently I've been going through the music subject headings and it can be a challenge for those of us who are musically challenged (and even those who know a little something about the subject).
One thing about Sears is that they direct one to use the "names of musical forms expressed in the singular, ... for both musical scores and for materials about the musical form, e.g. Concerto...."
LC allows two subject heading for such items, Concerto for the form and Concertos for the musical scores.
LC also uses the singular form for musical instruments, e.g. Piano, whereas Sears uses the plural form, Pianos. Both allow for forms like Piano music for the music played on such instruments.

I had to catalog videos about several Japanese instruments: the biwa, the shamisen, and the koto (kinds of lutes), and the shakuhachi (a kind of flute). I used the plural form for each instrument, e.g. Biwas, Shamisens, Kotos, Shakuhachis, with additional headings, Musical instruments--Japan, and the headings for Lute music or Flute music as appropriate. I could have used Biwa music, etc. but decided that was going too far.

Dewey can also pose a challenge for musical instruments because not all such exotic instruments are indexed and so trying to figure out whether an instrument fits in 787.7 (Zithers and lyres) or 787.8 (the plectral lute family) can also be difficult. Fortunately both biwas and shamisens are indexed as part of 787.85 (flat-backed lutes), but kotos are not indexed and even Wikipedia is not much help to the uninitiated. Using OCLC's Classify I found that others had classified the koto in 787.75. It seems that the instrument is a kind of "plucked zither." Who knew!

The best online tool right now for getting Dewey numbers for exotic topics is OCLC's Classify website. It shows the classification (both LC and Dewey when available) for items with specific subject headings. This site has been a godsend for me and I have it open along with the LC Authority page and WebDewey (subscription required) whenever I'm cataloging.

Messengers to Microprocessors

Image via WikipediaImage by Carosaurus via FlickrMessengers isn't a given Sears subject heading but is inferred from: Persons SA classes of persons, e.g. Elderly; Handicapped; Explorers; Drug addicts; etc. [to be added as needed]
One of the nice things about Sears is those generic terms which can be expanded "as needed." I do check LCSH Authorities to see whether such a heading was listed and it was.
Unfortunately, Microorganisms does not have a similar note so the list of choices is limited to Bacteria; Protozoa; and Viruses. Not very helpful. I had to catalog a film about the red tide (a toxic dinoflagellate bloom) so I added Dinoflagellates and Red tide to the record. Both are LCSH. I could have used the more generic Algae for dinoflagellates but specificity is good in a record. Besides, dinoflagellates are curious critters since both botany and zoology have claimed them. It's only fairly recently that some kind of agreement has been reached about their classification. See Wikipedia article for more info.
BTW, Sears is mistaken to make Marine plants a broader term for Algae since not all algae are marine. It also doesn't cross reference Algae from Microorganisms, which could be helpful.
I just confirmed that the use of Dinoflagellates can be inferred from the following: Plants SA ... names of categories of plants, e.g. Ferns [to be added as need]. Aha!

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Mental illness

Got through Mental illness and Mentally ill with all its subheadings.
In Sears there is no real provision for heading for people with specific illnesses, e.g. Schizophrenics, Manic-depressives, etc. so I use the heading for the disease along with the Mentally ill heading.

Mental health and a problem with juvie fiction

Image via WikipediaFinishing up "Mental health" today.

One problem I've discovered is that when the Library of Congress subject headings are not deleted or changed in a record fiction books can display without the subdivision because "Juvenile fiction" in some library catalog software. For example, the book Border Crossing by Jessica Lee Anderson has two subject headings when it comes from Alliance +, Mental illness--Juvenile fiction (Library of Congress) and Mental illness--Fiction (Sears). The problem comes because our catalog software, Destiny, does not display the Juvenile fiction subheading so it looks like this is a non-fiction book about mental illness. The solution is to either change the LC subdivision to Fiction or delete it entirely. I choose to delete it--along with all the other irrelevant or duplicated LC subject headings. This makes it far less confusing for the patron when searching for non-fiction books about a topic in the catalog.

Curriculum Video On Demand issues

Starting on the subject heading, "Men," today.

I've updated over 2000 of the Curriculum Video On Demand records since beginning of the project--that's about one-third of the approximately six thousand records done at this point. New records are added each month so it will definitely be an ongoing project. I am deleting some older or less relevant records as I go along.

Since they usually don't have good subject headings and many irrelevant or peripheral ones, Karlene, my assistant, and I spend a lot of time just deleting those unneeded headings. Here's an example of a MARC record as it comes from Infobase Learning before editing and here's the record after editing.