Last week's post on the rule of application noted that this rule has been woven into the schedules of the DDC and promised this follow-up post with further examples. In the meantime, Juli's post on recycling plastics concluded in this manner:
It should come as no surprise that works on recycling specific materials are classed according to the rule of application: recycling applied to plastics classed with plastics, recycling applied to a specific kind of plastic classed with the kind of plastic, recycling of specific kinds of wastes classed with specific kinds of wastes. . . . Nevertheless, it is still necessary to check the Relative Index and notes to see exactly what DDC numbers should be used.This post proceeds along two avenues. We will start with two large-scale implementations of the rule of application in the schedules. Then we will consider several recent developments in the schedules that have been driven by the rule of application.
One large-scale implementation of the rule of application is found in 610 Medicine and health with regard to the relationship between 615 Pharmacology and therapeutics and 616 Diseases. This relationship is so crucial that the rule of application finds explicit statement in the schedules, even though it is standard operating procedure (pun intended!). At 615.5 Therapeutics we find the following scatter class-elsewhere note:
Class therapies applied to a specific disease or group of diseases with the disease or group of diseases in 616–618, plus notation 06 from table under 616.1–616.9, notation 06 from table under 617, or notation 06 from table under 618.1–618.8, e.g., therapies for cardiovascular diseases 616.106
And at 615.7 Pharmacokinetics we find the following scatter class-elsewhere note:
Class use of a drug to treat a specific disease or group of diseases with the disease or group of diseases in 616–618, plus notation 061 from table under 616.1–616.9, notation 061 from table under 617, or notation 061 from table under 618.1–618.8, e.g., drug treatment for diseases of liver 616.362061
Therefore, for example, works on the treatment of arthritis using acupressure are classed in the number for arthritis (616.722 Arthritis) rather than in the number for acupressure (615.8222 Acupressure). Numbers for diseases allow for addition of notation from the internal add table under 616.1–616.9, where we find 06 Therapy and subdivisions, including 062-069 Other therapies, with an add instruction to add the numbers following 615.8 in 615.82–615.89. The specific number for treatment of arthritis using acupressure therefore is 616.72206222.
Another large-scale implementation of the rule of application is found in 780 Music. This time the rule of application finds form, not as an explicit statement in a class-elsewhere note, but as an implicit effect of the class-with-the-last preference order that governs the 780s. As pointed out in the Manual note for 780 Music, the usual arrangement or facet order in music is executant, form, general principles, and standard subdivisions. We find executants in 782 Vocal music, 783 Music for single voices, and 784–788 Instruments and their music; it is useful for our purposes to note that these numbers are not only for the voices and instruments that produce music, but also for the music they produce. We find musical forms that are executant-specific in the early numbers of their ranges (e.g., 782.1–782.4 Vocal forms, 784.18 [Instrumental] Musical forms) and those that are not executant-specific in 781.8 Musical forms. We find general principles that are executant-specific in the earliest numbers of their ranges (e.g., 782.01–782.07 General principles of vocal music, 784.11–784.17 General principles of instruments and instrumental ensembles and their music) and those that are not executant-specific in, e.g., 781.1 Basic principles of music, 781.3 Composition, and 781.4 Techniques of music. OK, so the class-with-the-last preference order implements the facet order (that is, executants come last, preceded by form, which in turn is preceded by general principles; and, as always, standard subdivisions come last), but what does this have to do with the rule of application? It’s this: processes and techniques that can be applied to music, e.g., composition, arrangement, performance, conducting, recording, are included in the general principles grab bag. Therefore—after the lengthy prelude, do we now need a drum roll? (oops, inflicting punishment again)—processes and techniques applied to musical forms or to music-by-kinds-of-executants are classed with the forms or executants. For example, works on the composition of fugues are classed in the number for fugues (784.1872 Fugues) rather than in the number for composition (781.3 Composition). Numbers for specific musical forms allow for addition of notation from the internal add table under 781.2–781.8, where we find 1 General principles and an instruction to add the numbers following 781 in 781.1–781.7. The specific number for composition of fugues therefore is 784.187213.
Now we turn to several examples, all involving computing, showing how the rule of application guides ongoing development of the DDC. We note first that works on the application of computers to a subject are classed in the number for the subject followed by T1—0285 Computer applications, if appropriate. Thus, when we relocated computational linguistics from 410.285 (Linguistics) Computer applications to 006.35 Natural language processing, it then became possible to express computational linguistics applications by adding T1—0285635, following the add instruction at T1—0285. Consistent with the rule of application, works on the use of natural language processing / computational linguistics to accomplish certain tasks are classed with the task, plus notation T1—0285635. Hence we get automatic abstracting 025.410285635 (025.41 Abstracting), word sense disambiguation 401.430285635 (401.43 Semantics), automatic part-of-speech tagging and automatic parsing 415.0285635 (415 Grammar of standard forms of languages), and machine translation 418.020285635 (418.02 Translating).
Questions on how to treat subjects like wireless Internet, wireless LANs, and wireless metropolitan networks were easily answered through the rule of application: class in the number for the kind of network. Therefore, wireless Internet is classed in 004.678, wireless LANs in 004.68, and wireless metropolitan networks in 004.67.
With DDC 23 additional concepts were incorporated into existing computer science classes. Two of these were integrated development environments (IDEs) and application frameworks. Webopedia describes an IDE as "a programming environment integrated into a software application that provides a GUI builder, a text or code editor, a compiler and/or interpreter and a debugger." So we had to decide whether to represent an IDE as a systems program (this is how interpreters, compilers, and assemblers are treated) or as an aid in programming (this is how application generators, text editors specially designed to assist in coding programs, and debuggers are treated). Since the rule of application sided with the latter, "integrated development environments" was added to the class-here note at 005.1 Programming. The pcmag.com encyclopedia characterizes an application framework as "a set of common software routines that provides a foundation structure for developing an application. Frameworks take the tedium out of writing all the program code for an application from scratch." As with integrated development environments, the purpose of application frameworks is to support the development of programs. The rule of application again leads to application frameworks being associated with 005.1 Programming, where "application frameworks" was also added to the class-here note.