Subject: Re: Knowledge classification systems (Was: Re: becoming a better programmer) From: Erik Naggum <firstname.lastname@example.org> Date: 17 Sep 2002 13:39:29 +0000 Newsgroups: comp.lang.lisp Message-ID: <email@example.com> * Frank A. Adrian | You've mentioned the Dewey Decimal System. I assume from the above that you | believe that other classifications would also be OK (Prytz, Library of | Congress, etc.) as long as the classification was universal and hierarchical | or do you also prefer numberical, as opposed to alphanumerical? I cannot find any useful information on Prytz, and I have not been able to figure out the Library of Congress system. I am comfortable with Dewey's and the Universal decimal classification system, probably because I remember numbers accurately without effort, while alphanumeric strings are lossy. Others I have talked to about this over the years see higher error rates in alphanumeric, including an unexpectedly interesting conversation with the designer of postal codes in Norway (which introduced them in 1968) and an equally unexpectedly entertaining conversation with the designer of the Norwegian social security number (introduced in 1964) -- I fear that such people are seldom recognized for their achievements. So I actually favor a system that is as simple as possible, possibly using coded representation of extraneous features. Dewey reserves 0 in subclasses and codes such things a geography, special subcategorization, etc, with 0 followed by additional digits. Thus the total number is a simple string of digits. UDC uses a more complex syntax which I personally find harder to remember. | I also find the ideas of a universal classification system useful, but I | have some things that bother me about the use of these systems when | searching for materials. | | First, hierarchical classifications are fine for finding books within a | given subject, but give no indication as to level. There are codes available for this in most of the existing systems. | Second, I wonder about stability of item location within the classification | system. This has become a more significant issue. If you look for the Library of Congress Cataloging-in-Publication Data of most U.S. imprints, you will find the Dewey code after the LC classification (a.k.a. call number) and year and before the LCCN (control number). Book Ed Year Dewew CIP LOC Common Lisp the Language 1984 001.64'24 (dc19) 2nd 1990 005.13'3 (dc20) Winston & Horn: Lisp 2nd 1984 001.64'24 (dc19) 3rd 1989 005.13'3 (dc19) James Gleick: Chaos 1988 003--dc19 Structure and Interpretation 1985 001.64'24 (dc19) of Computer Programs 2nd 1996 005.13'3--dc20 Introduction to Algorithms 1989 005.1--dc20 2nd 2001 005.1--dc21 The addition of the DDC edition in the Dewey code started with DDC 19, but was recommended with DDC 20 and mandatory with DDC 21. DDC 22 is due out next year. We see that programming languages moved from DDC 19 to DDC 20, with at least one book published before DDC 20. (I included the last two items just to show that things also do not move. :) | I remember finding a 1960's technical report on SNOBOL from Bell Labs back | in 1972 and thinking that this was already "historical material". But while the material itself is historical, the subject matter is not. The crucial difference between here is in the intent of the publication. | If I found it today, I'm pretty sure it would be better classified under | history of computing and not programming. That would require an arbitrary decision as to "currentness" of the material, which is explicitly excluded from consideration in classification. | In subclassifications dealing with rapidly changing topics, I could see this | becoming an issue. Strictly speaking, topics do not change, but new subclasses are frequently added and guidance on classification is published by the OCLC. E.g., I was happy to find "Semantic Web" classififed there as 025.04 for me when I did not find an obvious classification for it. The world-wide agreement on the application of and changes to the Dewey classification is a fascinating thing it itself. | I guess I'm wondering if any single ontological system really works that | well, or if a linearization of a multi-dimensional or networked system might | be better. In any case, I am, of course, thankful for what we currently | have! Many are surprised to find that DDC and UDC are multidimensional. | Finally, just a note of curiosity. While looking for information on library | classification systems, I noticed that Finland uses a Dewey derivative | called YKL. Does Norway also have its own derivative for its libraries or | does it follow Dewey's system? Just this week, the Norwegian Library Association published its 5th edition, a translation and adaptation of the 21st edition of DDC (i.e., including a number of pre-built numbers for typical Norwegian uses and downplaying classes that are more fine-grained in the U.S., particulary the 800 class (literature)). We have been lagging behind the U.S. development and only now prepare to reclassify public administration (350-354), education (370) and life sciences (560-590) according to DDC 21. The Oslo public library system (Deichmanske), being as it was the first library in Norway to adapt and apply Dewey's classification in 1898, have been a leading force in the application of Dewey in the Nordic countries and have resisted the temptation to make the kind of renegade changes that plagued many other Norwegian public libraries a few decades ago. -- Erik Naggum, Oslo, Norway Act from reason, and failure makes you rethink and study harder. Act from faith, and failure makes you blame someone and push harder.