School library and the Children's section of the public library Market.
* approximately
* 120 000 schools in the country,
* 70,000 elementary schools in the country,
* 7,000 public libraries.
* 0 training of both groups of librarians -

* Summary: Technical Stuff

What do Librarians Look For?

Librarians Read Reviews Then Order

The library of Congress provides two types of classification to books it catalogs for its collection.
Subject classification applies verbal subject terms to a book which describe the books overall content. Frequently the Library of Congress subject headings applied to a book may be found in the book itself on the reverse side of the title page. These subject headings are provided in a subject heading thesaurus, similar in structure to the thesauruses used for databases like ERIC, MEDLINE and other bibliographic databases. The thesuaurus for the Library of Congress is a multi-volume publication.

Subject Cataloging Division, Processing Dept.
Library of Congress, 1997

Like the subject heading words assigned to a book and provided on the subject catalog records (they were once printed cards filed alphabetically in drawers), the call numbers assigned to a book in both Dewey Decimal and Library of Congress classification are an assignment of to the book of a numerical statement of its most specific subject, the topic the book is most about, no easy task in today's times of complex interdisciplinary topics. The Dewey Decimal system is a rigid and limited system that permits little subdivision because the numbering system is so tightly utilized. The classification scheme is laid out in two volumes, a classification volume and an index volume. Dewey is most suitable for small topically diverse collections such as small rural public libraries.

The Library of Congress Classification system is published in over twenty volumes and each volume covers a Library of Congress Class or part of a class. The class would be one of the basic letters in the system such as class A which would be for general publications or class H which would be for social sciences or class Q which is devoted to the pure sciences. In class H the second letter subdivisions would include divisions like H itself for publications that are broadly social science, HA for statistics publications and publications of statistical data not specific to some subject field like education or banking. Class HB is for economics while class HC is for economic history. Numbers within each class further subdivide the subject field to specific subtopics within the discipline. The Library of Congress subject classification (call number) system is so precise that there is actually a Library of Congress classification designation for historical books about Walnut Street in Philadelphia. It is also a porous system that has a great deal of unused classification destinations throughout the system at all levels of the classification hierarchy.

Here is the catalog record for one of the volumes in the Library of Congress classification multi-volume set:

Corp author Library of Congress. Subject Cataloging Division.
Title Classification. Class P, subclasses PL-PM : languages of Eastern Asia, Africa, Oceania, hyperborean, Indian, and artificial languages / Subject Cataloging Division, Processing Services, Library of Congress.
Imprint Washington : The Library : For sale by the Cataloging Distribution Service, Library of Congress, 1988.