The Development of the Medical Literature Analysis and Retrieval System (MEDLARS)*
Dee, Cheryl Rae, Journal of the Medical Library Association
Objective: The research provides a chronology of the US National Library of Medicine's (NLM's) contribution to access to the world's biomedical literature through its computerization of biomedical indexes, particularly the Medical Literature Analysis and Retrieval System (MEDLARS).
Method: Using material gathered from NLM's archives and from personal interviews with people associated with developing MEDLARS and its associated systems, the author discusses key events in the history of MEDLARS.
Discussion: From the development of the early mechanized bibliographic retrieval systems of the 1940s and to the beginnings of online, interactive computerized bibliographic search systems of the early 1970s chronicled here, NLM's contributions to automation and bibliographic retrieval have been extensive.
Conclusion: As NLM's technological experience and expertise grew, innovative bibliographic storage and retrieval systems emerged. NLM's accomplishments regarding MEDLARS were cutting edge, placing the library at the forefront of incorporating mechanization and technologies into medical information systems.
The US Congress established the National Library of Medicine (NLM) to assist the advancement of medical and related sciences . In response to its Congressional mandate, NLM provides electronic and print access to reliable health information in the form of catalogs, bibliographies, indexes, and online databases [1, 2] to aid in the dissemination and exchange of scientific information . During the last fifty years, the health sciences field has produced an explosion of biomedical research and related publications to the extent that NLM accelerated investigation of new information technologies  to ensure the world biomedical community's access to scientific information [4, 5].
This paper sketches the chronology of the mechanization and computerization of medical indexes and bibliographic searching beginning with the early mechanized systems (1940s) and going forward to the introduction of the online computerized bibliographic search systems (1970s). The paper focuses on NLM's development of new methods for processing, organizing, and disseminating health information and illustrates how the library's experience and expertise developed NLM's Medical Literature Analysis and Retrieval System (MEDLARS) and MEDLARS II. The paper presents a selective rather than a comprehensive discussion of the events and systems leading to MEDLARS given the complexity of factors involved in MEDLARS' development.
EARLY STEPS TOWARDS INDEX MECHANIZATION
The chronicle of NLM's commitment to delivering information to health care professionals is deeply rooted in early historical indexing. NLM's indexing tradition began with Dr. John Shaw BUlings, the first director of " the Librarsssy of the Office of the Surgeon General of the US Army 1867-1895 (later named the National Library of Medicine) . Dr. BUlings formulated the Ubrary's mission to acquire, catalog, and index the literature of the medical sciences  and compiled the first medical index , the 1879 Index Medicus , foUowed in 1880 by the Library of the Surgeon General's Office Indexcatalogue . The library subsequently published a notable series of comprehensive printed biomedical indexes from 1916 to 1959 [11-13]. Around the close of World War II, the American Library Association (ALA) Survey of the Army Medical Library challenged the library to modernize the printed indexes and recommended a renewed effort to analyze the functions of the three major indexes . Specifically, the indexes were the American Medical Association's Quarterly Cumulative Index Medicus (1927-1956) , Current List of Medical Literature (1941-1959) , and the Army Medical Library's Index-Catalogue of the Library of the Surgeon General's Office , all of which were significantly behind their publication deadlines [15, 16].
The labor-intensive process to produce the printed indexes in the mid-1940s demonstrates the reason for the indexes' publication delays and the ALA recommendation. …