A workshop on the NLM Classification scheme:

for the

International Society of Knowledge Organization Student Group, SLAIS

Dean Giustini, Adjunct faculty, | February 27th, 2014

Reading an NLM call number

WE (broad class, go to Ws, then A, B, C, D….)

100 (read as a whole number from 1 to 999)

.Z18 (read alphabetically, then as a decimal)

2014 (year published, file in chronological order)

An NLM call number

• Each NLMC call number has several components:

WE 100 Z18 2014

Year physical item was published

Why is this useful?

Two letters indicatebroad subject

What is WE??Subcategory Z18?

• A classification system for physical materials in medicine• There are two main “schedules” • QS-QZ & W-WZ (left empty in LOC)• Topics organized by human physiology, body systems & medical disciplines• Within each “schedule”, division by organ has priority

• LC & NLM are used for subjects bordering on medicine• However, LC schedules for Human Anatomy (QM), Microbiology

(QR) and Medicine (R) are not used by NLMC• schedules start with “form numbers“ | publication types

ranging from 1-39 (helpful for browsing shelves)

Background on the NLMC

Quick history:• 1836: Library of the Surgeon General's Office• 1889-1890: Index to the medical literature began• 1922: Army Medical Library• 1944: Need for a new specialized medical classification system

recognized• 1951: First ed. Army Medical Library Classification• 1956: National Library of Medicine founded

• Largest medical collection in the world• Developed & maintains the NLM Classification • Medical Subject Headings (MeSH)

• MEDLINE, PubMed• UMLS (Unified Medical Language System)

Origins of a medical library

Origins of NMLC

“The genesis of the NLM classsification was a Survey of the Army Medical Library, published in 1944, which recommended that the “Library be re-

classified according to a modern scheme,” and that new scheme be a mixed notation (letters & numbers) resembling that of the Library of Congress.”

• From NLMC fifth edition (1994):

"The National Library of Medicine Classification covers the field of medicine and related sciences, utilizing schedules of QZ and W-WZ

permanently excluded from LOC.“

• Used worldwide to organize “classify” materials in medicine • Suitable for large & small libraries• Patterned after Library of Congress (LC) scheme• uses same principle of letters for broad subjects for browsing• subdivided by numbers • "cuttered" see Charles Ammi Cutter

What is the NLM Classification?

• Well-suited to (for) most medical libraries (esp. academic medical)• Simple, highly enumerative structure• Easy to apply…extensible• Clear division between preclinical & clinical topics• Serials are separated by form apart from monographs• Accommodates LCC for non-medical works• Less structured than Dewey’s classification system

• Does not express relations among classes • Not very good at accommodating new subjects

• Alternative & non-Western medicine• Health administration & public health

Strengths of the NLMC

Important: The NLMC is compatible with MeSH

“…The majority of medical libraries use the NLMC because it is “the most detailed and appropriate for a medical collection and provides

the best coverage for the subject.” (Womack, 2006)

In wide usage worldwide

…though some academic medical libraries use the “R” schedule in the LOC

• Allows for easy browsing of print collection• Easy to obtain records for cataloguing purposes• Updated annually • Most medical school libraries use it

• Schedules start with “form numbers“ (represent publication types) numbers range from 1-39

• Used as mnemonic devices for browsing by users

• NLMC & Medline used together, articles to monographs

• MeSH uses vocabulary medical professionals use

• LCSH is better for popular/consumer terms

Benefits of using NLMC