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An enhanced miniMEDLINE SYSTEM™: Abstracts, more journals, and CD-ROM
An Enhanced miniMEDLINE SYSTEM'M: Abstracts, More Journals, and CD-ROM Naomi C. Broering, M.L.S., M. A., Robert H. Larson, M.L.S. Helen E. Bagdoyan, M.L.S. The development of end-user information systems has attracted increasing attention during the past few years. Commercial vendors, publishers, database developers, a n d libraries are actively exploring new means of reaching the end-user by making direct computer-searching services available. For these efforts to be successful, it is essential to design a system that is easy to use, or userfriendly. This paper presents an overview of miniMEDLINE, a user-friendly bibliographic system developed by the Georgetown University Medical Center, and notes recent enhancements of, and future plans for, this unique end-user service.
BACKGROUND
Broering and Bagdoyan are librarians, and Larson is a systems analyst, at the Dahlgren Memorial Library of Georgetown University in Washington, DC. The authors make the following acknowledgements: We wish to thank Walter Bechtold, D.D.S., for his encouragement and his insistence that this project was technically feasible. We also wish to acknowledge Alan Zuckerman, M.D., for developing the initial programs. To those who have subsequently enhanced and maintained the system, Susan Anderson, James Kiesel, Karen Kerlin, and Bonnie Cannard, we owe our deepest gratitude. Lastly, but importantly, we thank Julie M. Ross for preparing the final manuscript. miniMEDLINE is a trademark of Georgetown University.
The miniMEDLINE SYSTEM is an inhouse database maintained in the Medical Library's DEC PDP 11/44 minicomputer. It is a self-service bibliographic component of the Georgetown University TM Library Information System (LIS) consisting of a subset of MEDLINE, the National Library of Medicine's (NLM) database. It includes over 200,000 citations of articles indexed in 461 clinical and science journals from 1983 to the present. Like MEDLINE, the database is updated monthly. The subject authority, MESH, is updated annually. The system allows users to instruct themselves in its use. It can be learned in only a few minutes because it accepts natural language. This is made possible through the interface with the NLM MeSH terms for the retrieval of article citations. The miniMEDLINE SYSTEM is offered as an inhouse,
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collection-oriented search service to meet i m m e diate needs for health i n f o r m a t i o n rather than as a means of addressing scholarly needs of researchers. It is used by students, young researchers, residents, and faculty members seeking quick answers to educational or clinical questions that might not warrant the costly and less convenient M E D L I N E search. ~
1
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DO you want to see a list af Journals indexed in ~ e ~iniMEOLI~E SYSTEM) Y/N Journals Indexed in the mlnlNEDLINE SYSTEM ~s
~ j p,thol J Phys Meal ~ J Physiol M~ J P S y c h i a t r ~
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SYSTEM D E S I G N Journals [ n d e x d in The miniMEOLINESYSTEM
The m i n i M E D L I N E SYSTEM is not meant to be comprehensive; its scope is intentionally narrow. It cites only a limited n u m b e r of journals, but users are assured that those journals are available in the library. Users t h e r e f o r e need not wait for interlibrary loans. When m i n i M E D L I N E was designed in 1982, the key fields saved f r o m the M E D L I N E unit record included author, title, source journal, and subject headings. Abstracts were not included. The m i n i M E D L I N E SYSTEM began with only 100 journals, and cited only articles for the current year. The database was created through a d o w n loading process of formulating a search strategy for the selected journals and capturing the data through a dial-up to the M E D L I N E system. Within a year, the demand users made on the system made it necessary to expand m i n i M E D L I N E to include at least 125 titles, and to increase coverage to two years. ~
B E G I N N I N G OF T H E "NEW LOOK" In recent years, the m i n i M E D L I N E software has been enhanced extensively. Georgetown expanded the file in 1984 to include 163 journals and three years of citations of journal articles. (See figure 1.) Thanks to the NLM's release of the M E D L I N E subset tapes in January 1985, the database is no longer acquired by downloading. (This was an inefficient means of building the database because "noise" on communications lines often resulted in transmission errors). The N L M tapes have also facilitated the inclusion of abstracts that were continually requested by users. There is now more flexibility for creating databases. In addition, the enhanced software has enabled other libraries that have replicated the miniM E D L I N E SYSTEM to select the journals they wish to cite in their inhouse database.
S E L E C T I O N OF J O U R N A L S The selection of journals for the m i n i M E D -
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Ann Otol Rhinal Laryngol A.n SUng ~ n thorac Sue9 Arch O ~ t o l
Bl~d Br Heart J f i r J Obstet GynascM Br J Pharmacol
Arch Ols Child Arc~ Envlr~ Health
Br J Rmdiol lr J Rh~atol
Arch Gm P s y c h i l t r y Arch I . t ~ n Med
8r J $urg B~ ~ed J CHn Res
Arc. o r , i BiOl Arch Otolcryngol Arch Path01 Lab M ~
CA Can J Mi~crobiol Can Ned Assoc J
Journals Inde,ed in The mniMEOLl~[ SYSTEM C~cul.tio~ Olin Orth~p CHn p c ~ i a t r [Phila) cl~n paa~=*col l h ~
Crlt C*~e Med
~ospltals H ~ pathol
l n t J Rad~at O~col Bid Phys J ^11~9y ci~. I ~ n o l J ~ O~t Assoc
Curt Probl Surg OM
J Am ~let ASSOC O ~ p l P~ys~o~
Dimbetes
J Bact~lol
0~9 ols Sc~ Or~g Metab Oispos [ndocednology Eur J Pharmacol Gsstroet~ulogy
J J J J J
G~iltric s Gut
j Clln Invest J Clln Pathol
Heart Lung ~$p Pt&ct press RETURN to continue
J O~t R ~ J Flm Pract
~lol ~ m Bo.e Jul.t Surg A~ Bone ~i.t Sutg Br Cell Biol Clln [ndocrlnol Metab
Figure 1: Sample of Journal List Available to Users of the miniMEDLINE System. ¢
L I N E SYSTEM is an evolving, dynamic process involving the participation of librarians and end-users. Two major criteria guide the choice of journals to be included in the database: the journal must be indexed in M E D L I N E and must be in the library's collection. The original database stressed clinical specialties and included citations f r o m journals in the Abridged Index Medicus; these were augmented by nursing and dental titles suggested by faculty. In 1983/1984, a survey of faculty in six science departments (anatomy, biochemistry, microbiology, pathology, pharmacology, and physiology/biophysics) resulted in the inclusion of more subjects and abstracts, and the expansion of the database. When the N L M made the M E D L I N E tapes available in 1985, G e o r g e t o w n subscribed to the entire file. This made it possible to compare the percentage of the citations in m i n i M E D L I N E that were used with the total n u m b e r of citations in each month's M E D L I N E file. The 163 miniMEDL I N E journals indexed in 1985 represented only 5 percent of the M E D L I N E database at that time; however, the references loaded f r o m the N L M tape for these journals represented more than 20 percent of the M E D L I N E database. A well-selected portion of the database, only 5 percent of the journals
of an immense file, captures a great portion of the system's contents. The miniMEDLINE journals are also the library's most heavily used journals. Early in 1986, because of an increase in the storage capacity of the library's computer disk, and the patrons' interest in seeing more journals included, the library decided to enlarge miniMEDLINE to include 416 titles. In selecting the journals to be added, the library considered the NLM's indexing priorities and the advice of Georgetown's faculty, and reviewed indexes of medical, dental, and nursing literature. NLM SUBSET TAPES The NLM distributes subsets of MEDLINE on 9-track tape in a form known as standard distribution format (SDF). This format consists of a variable-length record built up from a series of data elements. This variable-length record resuits in a very compact file for subset distribution, but poses several challenges for reading in a MUMPS environment. Processing a tape includes reading a record and simultaneously translating it from MEDLARS character code to ASCII code. The journal title element of the record is compared against a journal authority maintained by the library. Records that pass the authority check are stored in an update file. After the entire tape has been read, the records in the update file are integrated into the main file system. Due to the MUMPS operating system's dynamic capability for reorganizing files, miniMEDLINE can be updated while in use; it is not necessary to shut the system down in order to reorganize the files.
FILE ARCHITECTURE Six types of files are used to implement miniMEDLINE: a citation file, an index file, an abstract file, an authority file, scratch files, and log files. The citation file holds all the data elements of one subset record, except for the abstract. It is used to display a citation and is the source of secondary keys for the index file. This file is organized by the primary key of the citation. The primary key is assigned to each citation as it enters the system. The index file is an inverted file of all the secondary keys of a citation; that is, the author, title, journal, and subject. All searching is done from the index file. The primary key is used as a pointer to the citation and abstract files. The abstract file contains the text of the
abstract. The authority file includes MeSH subject headings and journal titles. The authority files insure consistency in the creation and indexing of files. Scratch files are used to hold temporary data, and log files are used to hold user search sets and statistics from search sessions. The following rules of thumb are used to assign sizes to the files in the miniMEDLINE SYSTEM: Citation file: 600 bytes/citation. Index file: 800 bytes/citation. Abstract file: 1400 bytes/citation. Authority file: approximately 1 megabyte. Scratch files and log files: start empty and allow file to grow until purged. User Libraries
In November 1982, Georgetown University agreed to replicate the LIS and the miniMEDLINE SYSTEM at other libraries. The following are some of the medical center libraries that have contracted with Georgetown to implement the miniMEDLINE SYS-TEM: University of Texas at San Antonio Johns Hopkins University Yale University Texas College of Osteopathic Medicine Medical University of South Carolina University of Alabama at Birmingham St. John's Hospital, Tulsa, Oklahoma Texas Tech University Cornell University Medical College University of South Carolina Rush University Medical College of Georgia Thomas Jefferson University University of Nebraska Eastern Virginia Medical School Several other institutions are conducting the final planning necessary to acquire the system. There is a growing trend toward inhouse database maintenance in medical center settings; this trend has been accelerated by the availability of the NLM subset tapes. In less than three years the miniMEDLINE SYSTEM has proved itself transportable and easily managed by librarians. Because the system is modular, a library can install miniMEDLINE as a part of its initial automation and implement an integrated system later, when funding is available. A LOOK INTO THE FUTURE WITH COMPACT DISKS (CD-ROM) With the conversion programs recently devel-
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oped by Georgetown, libraries using m i n i M E D L I N E are able to refine their own databases by adding or eliminating journals. The libraries acquire the tapes f r o m the N L M or NTIS. With the G e o r g e town conversion programs in place, they process the monthly updates locally. Features planned for 1986 will f u r t h e r enhance the searching capabilities of the system. Libraries are increasingly interested in mounting a large portion o f the M E D L I N E database. A major obstacle to expanding a file to include 500 or 1,000 journal titles is the cost of increased computer power. The remarkable optical disk called C D - R O M (Compact Disk-Read Only Memory), which can hold up to 600 megabytes of data on a single, 12-centimeter (4.7-inch) platter, may represent the solution to the problems of storing enormous databases and catalogs. Fortunately for m i n i M E D L I N E , Digital Equipment Corporation (DEC) has combined the C D - R O M with a DEC Micro V A X II to create a new way to distribute and use large amounts of information. R e search is underway to test the feasibility of transferring 600 journal titles to a compact disk and loading the m i n i M E D L I N E software in the DEC Micro V A X II. There are several advantages to the DEC system. It is the first to o f f e r an approach integrating hardware, software, and support. The DEC Micro V A X II has shared logic and networking capabilities. Unlike most other microcomputers it handles multiple tasks and multiple users. DEC computers are known for their reliability. Furthermore, the M U M P S environment runs well on DEC equipmentfl Georgetown is preparing a disk to test whether the m i n i M E D L I N E software and the database can be transferred to a C D - R O M environment on the Micro V A X II. Obviously, software modifications and conversions would be necessary before a new version can be released. The N L M has been very cooperative in the research project Georgetown is pursuing. H o w e v e r , a great deal of work needs to be accomplished before a new version can emerge f r o m a research mode to an application mode. Progress will depend largely on our ability to overcome design and development hurdles and on disk production schedules, which are currently extremely slow. The move f r o m the research laboratory to the library setting is more complex than one might imagine. Costs are of major concern. Because the m i n i M E D L I N E is updated monthly, twelve new disks are required per year; each costs approximately $10,000, for a total of $120,000. Obviously, this is only part of the cost of production. There are others such as fees for the NLM's database, mass production, dissemination, distribution, soft-
36
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ware design, and administration of the system. The fact that many libraries want the new version of the m i n i M E D L I N E software suggests that George. town will be able to take advantage of economies of scale. M i n i M E D L I N E was intended to provide free access to users in medical centers by maintaining an inhouse database for repeated use. Although it may be technically possible to expand the concept of an inhouse database, many questions concerning the cost of the database and the way it would be used must be answered before the database could be developed for widespread use. C D - R O M Storage There are three technical issues involved in adapting the m i n i M E D L I N E SYSTEM to use CDR O M storage: the modification of the operating system, the modification of the application programs, and the production of the C D - R O M . In the initial experiment testing the adaptability o f the m i n i M E D L I N E software, the r e a d - o n l y nature of the C D - R O M made it incompatible with the version o f ANS MUMPS that G e o r g e t o w n uses on the V A X minicomputer, causing problems with the existing applications software. The scratch and log files require continual updating and must be located on a read-write device. To solve this problem, Georgetown enlisted the help of Inter-Systems Corporation (the Boston f i r m that sells the ISM MUMPS operating system) to design m i n i M E D L I N E version 3.1 with distributed database capabilities. Each file of version 3.1 is d e f i n e d in a table that tells the operating system which i n p u t / o u t p u t device and even which computer to use to access a particular file. The first four types of files, which are updated infrequently, are d e f i n e d to be stored on the CDROM. The dynamic scratch and log files are defined to be located on a Winchester disk, which has highspeed access and r e a d / w r i t e capabilities. The actual C D - R O M production consists of submitting 1/2-inch magnetic tapes to the Mastering Services Department of Digital E q u i p m e n t Corporation. The tapes are created from the miniMEDLINE database, which has been specially processed to hold as many data as possible and to ensure a contiguous file structure. The access time of a CDR O M is very slow, relative to a magnetic disk, so it is important that this step be carried out.
SYSTEM O P E R A T I O N For the benefit of practicing librarians, operational aspects of miniMEDLINE, including hardware/software, system use, maintenance costs and user behavior, are also covered in this paper.
Hardware/Software In an academic medical center where miniMEDLINE is used frequently and by many people, the m i n i c o m p u t e r - b a s e d software version is recommended because it has shared logic and timesharing capabilities, and functions at 9,600 baud. The m i n i M E D L I N E SYSTEM operates on any DEC PDP 11 or V A X series minicomputer. The current database consumes an entire disk drive of 400 to 600 megabytes. E a c h year's file requires approximately 200 megabytes of storage, depending on the n u m b e r of journals in the database. At Georgetown, m i n i M E D L I N E runs on the library's DEC PDP 11/44 minicomputer; the computer has four disk drives, which together have 1,500 megabytes of storage capacity. M i n i M E D L I N E can also run on a DEC V A X 785 minicomputer with similar disk storage capacity. The system's software is programmed in the ANS MUMPS language, using an Intersystems ISM11+ operating system. The structure of the ANS MUMPS database provides rapid access to r e f e r ences in the database.
User Access Because the system is maintained in the library's dedicated computer, it is available during all the hours the library is open, and practically t w e n t y - f o u r hours a day for users with home computers. It is provided free to registered library borrowers, including Georgetown University's faculty, staff, students, residents, and fellows. Users gain access to the system from terminals located in the public areas of the library and from remote sites throughout the medical center. There are currently five hard-wired, remote w o r k stations, located in the schools of nursing, d e n tistry, and medicine, in the university hospital, and in a basic sciences department. ADM5 and A D M l l C R T terminals f r o m Lear Siegler and OKIDATA's microline 82A printers are used by library patrons and at the remote sites. In addition, approximately sixty users with data terminals or personal computers in their homes or offices have access codes for the library's system. These users can conduct searches using m i n i M E D L I N E f r o m wherever they are located. A local area network (LAN) is being installed to accommodate the demand users are placing on the system. Tile Search Steps The m i n i M E D L I N E SYSTEM uses a " p u s h - b u t ton" approach to searching. It requires little typing and f e w key strokes. It is m e n u - d r i v e n . (See figure 2.) The menu consists of nine options
SEARCHOPTIONS: 1 Author Z T i t l e Word 3 Journal 4 Subject DISPLAY OPTIONS: 5 References from a single Set 6 A l l References from more than one Set (Boolean OR) 7 Co~ine' References Commonto two or more Sets (Boolean AND) OTHER OPTIONS: 8 Delete a l l sets and begin a new search 9 qutt CHOICE?
Figure 2: Menu Used to Generate Searches.
and only two search steps and one printing step, the latter being automatically generated for the user at the end of the search. In the first step, the sets of citations can be built by searching any of the f o u r index fields: author, title word, journal, or subject. Truncated k e y - w o r d searching can be carried out directly on titles and the names of authors. The N L M MeSH vocabulary file and a file of journal titles serve as intermediary authority files to improve the user's e f f i c i e n c y in identifying subject headings and journal titles. The second step allows sets to be displayed singly or combined. (See the fifth, sixth, and seventh options in figure 2.) Citations in a set are displayed, one per screen, and saved so that selected citations can be printed later. (See figure 3.) The subject headings assist users in deciding whether to read an article or search using other headings. Abstracts, when available, are included in the database. The third step includes two options, which allow the user to begin a new search or to stop. 4 In the first step, for example, if a user were to search by a subject term, such as arthritis, the system would respond with all the references matching that term; in addition, it would provide more specific subheadings to enable the user to select appropriate references. (See figure 4.) The results of the first subject search would become Set A. The user could continue to search for any other options. If the user also knew of an author named Moore who had written an article on arthritis that might be pertinent, a search by author could be generated by typing in the name Moore. The system would retrieve all the authors' names in the file named Moore, with their first initials. This would allow the user to select one name, or to save all
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|
the end of the search the printer automatically produces the bibliography. The system is also capable of automatically providing a heading for the search and alphabetizing the journal titles. (Most medical libraries shelve journals in alphabetical order.) 5
| ~Reference 1 of I Lefc~ NM AshleyMO
Costs of Maintaining the System
Pederson l L Keays dJ The health risks of passive smoking. 3he growing case for control
~asures in enclosed environments. Chest. 8d(1):90-5. 1983 Ju]
Adult
CarbonMonoxide C~rdiovascular Diseases: c ~ i c a t i o n s Female H u m a n "Legislation • " : e i o ae
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C h i l d , Preschool
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TObacco Smoke P o l l u t i o n Legislation (581 A AND B (1) Lancet (DgDS) ~ti-lnfective Agents
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(2D)
Display Papers in SET? D
Combination of j o u r n a l t i t l e and Subject
AND also in SET? E AND also in SET?
i _
Reference 2 of 4 Greenwood D Laveriek A A c t i v i t i e s of newer qutnolones a g a i n s t L e g i o n e l l a group organisms Lancet. Z(8344):279-B0. 1983 dul 30
letter
Anti-lnfectlve Agents: pharmacodynamic%* Drug Resistance, Microbial Leglonella: classification, drug effects" Nalldixi¢ Acid: analogs & derivatives', pharmacodynamies Qulnolines: 9harmaeodynamics" Enter RETURNto continue, P to print. D to go back, Q to qult
DETUR~/P/BIQ
Database development, equipment, computer storage, and online access are underwritten by the library. Because the major computer costs are absorbed by the library's internal automated system, it is difficult to separate some cost factors. Georgetown decided to make use of the flatfee option for the NLM tapes. Smaller versions at a reduced fee are available. The estimated costs of creating and maintaining the database are given in table 1 as a guide. These figures do not include the cost of the miniMEDLINE software applications programs, nor the cost of the hardware required to replicate the system. Table 1 : Annual Cost of Database Maintenance
Annual NLM fee for subset tapes Ongoing programming Preloading tapes Disk storage* Supplies Staff time (approximately 5 percent)*
Figure 3: Two-Step Approaches to Developing Sets for a Bibliography.
References i
$14,600
Clague RB Moore LJ IgG and IgM antibody to native type II collagen in rheumatoid erthrltls serum and synovlal f l u i d . . . ARTHRITIS RHEUM. 27(12):1370-7. 1984 Dec i Figure 4: Combining Terms by Building Sets.
the names if he was uncertain of the initials. These names would become Set B. The menu returns to the screen automatically to progress to the second step, the displaying of options. In this example, the seventh option (combine the references from both Set A and Set B) is selected; the match results in Set C. The references in Set C are then displayed. As the user reviews each citation appearing on the screen, he also has the option of retrieving the abstract. The user can select which citations to print; at
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Set A - Arthritis, Rheumatoid (753) Set B - MOORE L... (15) Set C - A AND B (1) Printout of References selected from set C Arthritis Rheum
38
$10,000 2,500 600 xxx 300
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(* Costs and salaries vary) System Use The miniMEDLINE SYSTEM has been well received by students and the faculty. Terminals, available throughout the library, are in high demand. The miniMEDLINE SYSTEM facilitates users' teaching themselves; still, under the tutelage of reference librarians, students, and faculty members are quickly developing sound information-seeking skills and a good comprehension of techniques for making use of the system's storage and retrieval capabilities (by using Boolean logic, for instance). The degree of sophistication patrons exhibit when using miniMEDLINE varies enormously. The analysis of data collected on the number of searches, types of users, options selected, time spent, and searches printed reveals some trends in the behavior of users during the past two years. (See table
2.) The statistical data show that over 36,000
Table 2: Statistical Data --
System Use
1-- Searches 2. Users (students, reslaents, faculty) 3. Time Spent (hours) Total Time (minutes) Average Time (minutes) 4. References Printed 5. Average References Displayed Average References Printed
7/836/84
7/846/85
2-Yr~ ' Total
16,897
19,142
36,039
2,311 3,518 211,098
2,549 3,645 218,684
4,860 7,163 429,782
12 99,662
11 150,351
11.5 250,013
42
53
47
6
8
7
searches were conducted in the most recent twoyear period. This represents almost five times the average number of MEDLINE searches conducted by the librarians. The 7,163 hours of computer "connect time," at $22 per hour, would have cost over $150,000 on MEDLINE. Because the miniMEDLINE SYSTEM runs at 9,600-baud, the average time spent per search is only eleven minutes. As noted above, users are able to refine their own searches quickly and print only those references they need. (See table 3.) Table 3: Analysis of Retrieval
Search Options Author Title Journal Subject
7/836/84 1,070 602 1,275 21,556
7/846/85 6,502 4,663 1,591 19,770
2-Yr. Total 7,572 5,265 2,866 41,326
Display Options Option 5 Single sets Option 6 Two or more sets (Boolean "or') Option 7 Combination of sets (Boolean "and")
21,045
25,876
46,921
11,105
14,719
25,824
1,454
1,711
3,165
These data support the theory that novices feel more comfortable working with searches for single subjects. More sophisticated users have learned to manipulate sets using the Boolean OR, but these patrons represent only 31 percent of the total number of users. Only 5 percent have learned to apply the more complex strategy of using Boolean AND logic. If a comparison is made between the two years, the figures indicate a slight increase in the sophistication of users. In the first year, 63 percent of the users retrieved single sets, while 33 Percent used Boolean OR, and 4 percent used Boo-
lean AND. In contrast, in the second year, the figures indicate a gradual shift from single sets (61 percent) to retrieval using Boolean OR (35 percent) and Boolean AND (7 percent).
CONCLUSION The miniMEDLINE SYSTEM is popular at Georgetown and is becoming successful nationally. Other medical libraries are already beginning to adopt the concept of a collection-oriented MEDLINE database with value-added, user-friendly features. Some libraries are designing their own search systems, a few are working with commercial vendors, and others are acquiring the miniMEDLINE software from Georgetown. The university provides assistance in implementing and maintaining the system, and trains the staffs of user institutions. The original miniMEDLINE SYSTEM is continually being enhanced. Georgetown has made numerous annual modifications. The NLM has permitted a feasibility study to test miniMEDLINE on CD-ROM. Indirectly, this has resulted in a cooperative project between Georgetown University, Digital Equipment Corporation, and the NLM in which research is being conducted using a new technology in a library setting. The system is currently undergoing testing. If successful, the results of this partnership can be shared with other libraries.
NOTES 1. N.C. Broering, "The miniMEDLINE SYSTEM: A Library-Based End-User Search System," Bulletin of the Medical Library Association 73 (April 1985): 138-145. 2. Georgetown University Medical Center, "Library Information System Manual" (Georgetown University, Dahlgren Memorial Library, 1984), G1. 3. "CD Reader and CD ROM: A Revolution in Information Delivery" (brochure, Digital Equipment Corporation, 1985). 4. N.C. Broering, "The Georgetown University Library Information System (LIS): A MinicomputerBased Integrated Library System," Bulletin of the Medical Library Association 71 (July 1983): 317323. 5. A.E. Zuckerman, "Bibliographic Systems," in Computers and Libraries." A Management Seminar, ed. N.C. Broering et al (Washington, DC: Georgetown University Medical Center, 1982): 52-58. @
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BACKGROUND
Broering and Bagdoyan are librarians, and Larson is a systems analyst, at the Dahlgren Memorial Library of Georgetown University in Washington, DC. The authors make the following acknowledgements: We wish to thank Walter Bechtold, D.D.S., for his encouragement and his insistence that this project was technically feasible. We also wish to acknowledge Alan Zuckerman, M.D., for developing the initial programs. To those who have subsequently enhanced and maintained the system, Susan Anderson, James Kiesel, Karen Kerlin, and Bonnie Cannard, we owe our deepest gratitude. Lastly, but importantly, we thank Julie M. Ross for preparing the final manuscript. miniMEDLINE is a trademark of Georgetown University.
The miniMEDLINE SYSTEM is an inhouse database maintained in the Medical Library's DEC PDP 11/44 minicomputer. It is a self-service bibliographic component of the Georgetown University TM Library Information System (LIS) consisting of a subset of MEDLINE, the National Library of Medicine's (NLM) database. It includes over 200,000 citations of articles indexed in 461 clinical and science journals from 1983 to the present. Like MEDLINE, the database is updated monthly. The subject authority, MESH, is updated annually. The system allows users to instruct themselves in its use. It can be learned in only a few minutes because it accepts natural language. This is made possible through the interface with the NLM MeSH terms for the retrieval of article citations. The miniMEDLINE SYSTEM is offered as an inhouse,
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collection-oriented search service to meet i m m e diate needs for health i n f o r m a t i o n rather than as a means of addressing scholarly needs of researchers. It is used by students, young researchers, residents, and faculty members seeking quick answers to educational or clinical questions that might not warrant the costly and less convenient M E D L I N E search. ~
1
W-----l
DO you want to see a list af Journals indexed in ~ e ~iniMEOLI~E SYSTEM) Y/N Journals Indexed in the mlnlNEDLINE SYSTEM ~s
~ j p,thol J Phys Meal ~ J Physiol M~ J P S y c h i a t r ~
Anlt (~asel) ~cta ~Ontol Scind
SYSTEM D E S I G N Journals [ n d e x d in The miniMEOLINESYSTEM
The m i n i M E D L I N E SYSTEM is not meant to be comprehensive; its scope is intentionally narrow. It cites only a limited n u m b e r of journals, but users are assured that those journals are available in the library. Users t h e r e f o r e need not wait for interlibrary loans. When m i n i M E D L I N E was designed in 1982, the key fields saved f r o m the M E D L I N E unit record included author, title, source journal, and subject headings. Abstracts were not included. The m i n i M E D L I N E SYSTEM began with only 100 journals, and cited only articles for the current year. The database was created through a d o w n loading process of formulating a search strategy for the selected journals and capturing the data through a dial-up to the M E D L I N E system. Within a year, the demand users made on the system made it necessary to expand m i n i M E D L I N E to include at least 125 titles, and to increase coverage to two years. ~
B E G I N N I N G OF T H E "NEW LOOK" In recent years, the m i n i M E D L I N E software has been enhanced extensively. Georgetown expanded the file in 1984 to include 163 journals and three years of citations of journal articles. (See figure 1.) Thanks to the NLM's release of the M E D L I N E subset tapes in January 1985, the database is no longer acquired by downloading. (This was an inefficient means of building the database because "noise" on communications lines often resulted in transmission errors). The N L M tapes have also facilitated the inclusion of abstracts that were continually requested by users. There is now more flexibility for creating databases. In addition, the enhanced software has enabled other libraries that have replicated the miniM E D L I N E SYSTEM to select the journals they wish to cite in their inhouse database.
S E L E C T I O N OF J O U R N A L S The selection of journals for the m i n i M E D -
34
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SUMMER AND FALL 1986
Ann Otol Rhinal Laryngol A.n SUng ~ n thorac Sue9 Arch O ~ t o l
Bl~d Br Heart J f i r J Obstet GynascM Br J Pharmacol
Arch Ols Child Arc~ Envlr~ Health
Br J Rmdiol lr J Rh~atol
Arch Gm P s y c h i l t r y Arch I . t ~ n Med
8r J $urg B~ ~ed J CHn Res
Arc. o r , i BiOl Arch Otolcryngol Arch Path01 Lab M ~
CA Can J Mi~crobiol Can Ned Assoc J
Journals Inde,ed in The mniMEOLl~[ SYSTEM C~cul.tio~ Olin Orth~p CHn p c ~ i a t r [Phila) cl~n paa~=*col l h ~
Crlt C*~e Med
~ospltals H ~ pathol
l n t J Rad~at O~col Bid Phys J ^11~9y ci~. I ~ n o l J ~ O~t Assoc
Curt Probl Surg OM
J Am ~let ASSOC O ~ p l P~ys~o~
Dimbetes
J Bact~lol
0~9 ols Sc~ Or~g Metab Oispos [ndocednology Eur J Pharmacol Gsstroet~ulogy
J J J J J
G~iltric s Gut
j Clln Invest J Clln Pathol
Heart Lung ~$p Pt&ct press RETURN to continue
J O~t R ~ J Flm Pract
~lol ~ m Bo.e Jul.t Surg A~ Bone ~i.t Sutg Br Cell Biol Clln [ndocrlnol Metab
Figure 1: Sample of Journal List Available to Users of the miniMEDLINE System. ¢
L I N E SYSTEM is an evolving, dynamic process involving the participation of librarians and end-users. Two major criteria guide the choice of journals to be included in the database: the journal must be indexed in M E D L I N E and must be in the library's collection. The original database stressed clinical specialties and included citations f r o m journals in the Abridged Index Medicus; these were augmented by nursing and dental titles suggested by faculty. In 1983/1984, a survey of faculty in six science departments (anatomy, biochemistry, microbiology, pathology, pharmacology, and physiology/biophysics) resulted in the inclusion of more subjects and abstracts, and the expansion of the database. When the N L M made the M E D L I N E tapes available in 1985, G e o r g e t o w n subscribed to the entire file. This made it possible to compare the percentage of the citations in m i n i M E D L I N E that were used with the total n u m b e r of citations in each month's M E D L I N E file. The 163 miniMEDL I N E journals indexed in 1985 represented only 5 percent of the M E D L I N E database at that time; however, the references loaded f r o m the N L M tape for these journals represented more than 20 percent of the M E D L I N E database. A well-selected portion of the database, only 5 percent of the journals
of an immense file, captures a great portion of the system's contents. The miniMEDLINE journals are also the library's most heavily used journals. Early in 1986, because of an increase in the storage capacity of the library's computer disk, and the patrons' interest in seeing more journals included, the library decided to enlarge miniMEDLINE to include 416 titles. In selecting the journals to be added, the library considered the NLM's indexing priorities and the advice of Georgetown's faculty, and reviewed indexes of medical, dental, and nursing literature. NLM SUBSET TAPES The NLM distributes subsets of MEDLINE on 9-track tape in a form known as standard distribution format (SDF). This format consists of a variable-length record built up from a series of data elements. This variable-length record resuits in a very compact file for subset distribution, but poses several challenges for reading in a MUMPS environment. Processing a tape includes reading a record and simultaneously translating it from MEDLARS character code to ASCII code. The journal title element of the record is compared against a journal authority maintained by the library. Records that pass the authority check are stored in an update file. After the entire tape has been read, the records in the update file are integrated into the main file system. Due to the MUMPS operating system's dynamic capability for reorganizing files, miniMEDLINE can be updated while in use; it is not necessary to shut the system down in order to reorganize the files.
FILE ARCHITECTURE Six types of files are used to implement miniMEDLINE: a citation file, an index file, an abstract file, an authority file, scratch files, and log files. The citation file holds all the data elements of one subset record, except for the abstract. It is used to display a citation and is the source of secondary keys for the index file. This file is organized by the primary key of the citation. The primary key is assigned to each citation as it enters the system. The index file is an inverted file of all the secondary keys of a citation; that is, the author, title, journal, and subject. All searching is done from the index file. The primary key is used as a pointer to the citation and abstract files. The abstract file contains the text of the
abstract. The authority file includes MeSH subject headings and journal titles. The authority files insure consistency in the creation and indexing of files. Scratch files are used to hold temporary data, and log files are used to hold user search sets and statistics from search sessions. The following rules of thumb are used to assign sizes to the files in the miniMEDLINE SYSTEM: Citation file: 600 bytes/citation. Index file: 800 bytes/citation. Abstract file: 1400 bytes/citation. Authority file: approximately 1 megabyte. Scratch files and log files: start empty and allow file to grow until purged. User Libraries
In November 1982, Georgetown University agreed to replicate the LIS and the miniMEDLINE SYSTEM at other libraries. The following are some of the medical center libraries that have contracted with Georgetown to implement the miniMEDLINE SYS-TEM: University of Texas at San Antonio Johns Hopkins University Yale University Texas College of Osteopathic Medicine Medical University of South Carolina University of Alabama at Birmingham St. John's Hospital, Tulsa, Oklahoma Texas Tech University Cornell University Medical College University of South Carolina Rush University Medical College of Georgia Thomas Jefferson University University of Nebraska Eastern Virginia Medical School Several other institutions are conducting the final planning necessary to acquire the system. There is a growing trend toward inhouse database maintenance in medical center settings; this trend has been accelerated by the availability of the NLM subset tapes. In less than three years the miniMEDLINE SYSTEM has proved itself transportable and easily managed by librarians. Because the system is modular, a library can install miniMEDLINE as a part of its initial automation and implement an integrated system later, when funding is available. A LOOK INTO THE FUTURE WITH COMPACT DISKS (CD-ROM) With the conversion programs recently devel-
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oped by Georgetown, libraries using m i n i M E D L I N E are able to refine their own databases by adding or eliminating journals. The libraries acquire the tapes f r o m the N L M or NTIS. With the G e o r g e town conversion programs in place, they process the monthly updates locally. Features planned for 1986 will f u r t h e r enhance the searching capabilities of the system. Libraries are increasingly interested in mounting a large portion o f the M E D L I N E database. A major obstacle to expanding a file to include 500 or 1,000 journal titles is the cost of increased computer power. The remarkable optical disk called C D - R O M (Compact Disk-Read Only Memory), which can hold up to 600 megabytes of data on a single, 12-centimeter (4.7-inch) platter, may represent the solution to the problems of storing enormous databases and catalogs. Fortunately for m i n i M E D L I N E , Digital Equipment Corporation (DEC) has combined the C D - R O M with a DEC Micro V A X II to create a new way to distribute and use large amounts of information. R e search is underway to test the feasibility of transferring 600 journal titles to a compact disk and loading the m i n i M E D L I N E software in the DEC Micro V A X II. There are several advantages to the DEC system. It is the first to o f f e r an approach integrating hardware, software, and support. The DEC Micro V A X II has shared logic and networking capabilities. Unlike most other microcomputers it handles multiple tasks and multiple users. DEC computers are known for their reliability. Furthermore, the M U M P S environment runs well on DEC equipmentfl Georgetown is preparing a disk to test whether the m i n i M E D L I N E software and the database can be transferred to a C D - R O M environment on the Micro V A X II. Obviously, software modifications and conversions would be necessary before a new version can be released. The N L M has been very cooperative in the research project Georgetown is pursuing. H o w e v e r , a great deal of work needs to be accomplished before a new version can emerge f r o m a research mode to an application mode. Progress will depend largely on our ability to overcome design and development hurdles and on disk production schedules, which are currently extremely slow. The move f r o m the research laboratory to the library setting is more complex than one might imagine. Costs are of major concern. Because the m i n i M E D L I N E is updated monthly, twelve new disks are required per year; each costs approximately $10,000, for a total of $120,000. Obviously, this is only part of the cost of production. There are others such as fees for the NLM's database, mass production, dissemination, distribution, soft-
36
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ware design, and administration of the system. The fact that many libraries want the new version of the m i n i M E D L I N E software suggests that George. town will be able to take advantage of economies of scale. M i n i M E D L I N E was intended to provide free access to users in medical centers by maintaining an inhouse database for repeated use. Although it may be technically possible to expand the concept of an inhouse database, many questions concerning the cost of the database and the way it would be used must be answered before the database could be developed for widespread use. C D - R O M Storage There are three technical issues involved in adapting the m i n i M E D L I N E SYSTEM to use CDR O M storage: the modification of the operating system, the modification of the application programs, and the production of the C D - R O M . In the initial experiment testing the adaptability o f the m i n i M E D L I N E software, the r e a d - o n l y nature of the C D - R O M made it incompatible with the version o f ANS MUMPS that G e o r g e t o w n uses on the V A X minicomputer, causing problems with the existing applications software. The scratch and log files require continual updating and must be located on a read-write device. To solve this problem, Georgetown enlisted the help of Inter-Systems Corporation (the Boston f i r m that sells the ISM MUMPS operating system) to design m i n i M E D L I N E version 3.1 with distributed database capabilities. Each file of version 3.1 is d e f i n e d in a table that tells the operating system which i n p u t / o u t p u t device and even which computer to use to access a particular file. The first four types of files, which are updated infrequently, are d e f i n e d to be stored on the CDROM. The dynamic scratch and log files are defined to be located on a Winchester disk, which has highspeed access and r e a d / w r i t e capabilities. The actual C D - R O M production consists of submitting 1/2-inch magnetic tapes to the Mastering Services Department of Digital E q u i p m e n t Corporation. The tapes are created from the miniMEDLINE database, which has been specially processed to hold as many data as possible and to ensure a contiguous file structure. The access time of a CDR O M is very slow, relative to a magnetic disk, so it is important that this step be carried out.
SYSTEM O P E R A T I O N For the benefit of practicing librarians, operational aspects of miniMEDLINE, including hardware/software, system use, maintenance costs and user behavior, are also covered in this paper.
Hardware/Software In an academic medical center where miniMEDLINE is used frequently and by many people, the m i n i c o m p u t e r - b a s e d software version is recommended because it has shared logic and timesharing capabilities, and functions at 9,600 baud. The m i n i M E D L I N E SYSTEM operates on any DEC PDP 11 or V A X series minicomputer. The current database consumes an entire disk drive of 400 to 600 megabytes. E a c h year's file requires approximately 200 megabytes of storage, depending on the n u m b e r of journals in the database. At Georgetown, m i n i M E D L I N E runs on the library's DEC PDP 11/44 minicomputer; the computer has four disk drives, which together have 1,500 megabytes of storage capacity. M i n i M E D L I N E can also run on a DEC V A X 785 minicomputer with similar disk storage capacity. The system's software is programmed in the ANS MUMPS language, using an Intersystems ISM11+ operating system. The structure of the ANS MUMPS database provides rapid access to r e f e r ences in the database.
User Access Because the system is maintained in the library's dedicated computer, it is available during all the hours the library is open, and practically t w e n t y - f o u r hours a day for users with home computers. It is provided free to registered library borrowers, including Georgetown University's faculty, staff, students, residents, and fellows. Users gain access to the system from terminals located in the public areas of the library and from remote sites throughout the medical center. There are currently five hard-wired, remote w o r k stations, located in the schools of nursing, d e n tistry, and medicine, in the university hospital, and in a basic sciences department. ADM5 and A D M l l C R T terminals f r o m Lear Siegler and OKIDATA's microline 82A printers are used by library patrons and at the remote sites. In addition, approximately sixty users with data terminals or personal computers in their homes or offices have access codes for the library's system. These users can conduct searches using m i n i M E D L I N E f r o m wherever they are located. A local area network (LAN) is being installed to accommodate the demand users are placing on the system. Tile Search Steps The m i n i M E D L I N E SYSTEM uses a " p u s h - b u t ton" approach to searching. It requires little typing and f e w key strokes. It is m e n u - d r i v e n . (See figure 2.) The menu consists of nine options
SEARCHOPTIONS: 1 Author Z T i t l e Word 3 Journal 4 Subject DISPLAY OPTIONS: 5 References from a single Set 6 A l l References from more than one Set (Boolean OR) 7 Co~ine' References Commonto two or more Sets (Boolean AND) OTHER OPTIONS: 8 Delete a l l sets and begin a new search 9 qutt CHOICE?
Figure 2: Menu Used to Generate Searches.
and only two search steps and one printing step, the latter being automatically generated for the user at the end of the search. In the first step, the sets of citations can be built by searching any of the f o u r index fields: author, title word, journal, or subject. Truncated k e y - w o r d searching can be carried out directly on titles and the names of authors. The N L M MeSH vocabulary file and a file of journal titles serve as intermediary authority files to improve the user's e f f i c i e n c y in identifying subject headings and journal titles. The second step allows sets to be displayed singly or combined. (See the fifth, sixth, and seventh options in figure 2.) Citations in a set are displayed, one per screen, and saved so that selected citations can be printed later. (See figure 3.) The subject headings assist users in deciding whether to read an article or search using other headings. Abstracts, when available, are included in the database. The third step includes two options, which allow the user to begin a new search or to stop. 4 In the first step, for example, if a user were to search by a subject term, such as arthritis, the system would respond with all the references matching that term; in addition, it would provide more specific subheadings to enable the user to select appropriate references. (See figure 4.) The results of the first subject search would become Set A. The user could continue to search for any other options. If the user also knew of an author named Moore who had written an article on arthritis that might be pertinent, a search by author could be generated by typing in the name Moore. The system would retrieve all the authors' names in the file named Moore, with their first initials. This would allow the user to select one name, or to save all
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|
the end of the search the printer automatically produces the bibliography. The system is also capable of automatically providing a heading for the search and alphabetizing the journal titles. (Most medical libraries shelve journals in alphabetical order.) 5
| ~Reference 1 of I Lefc~ NM AshleyMO
Costs of Maintaining the System
Pederson l L Keays dJ The health risks of passive smoking. 3he growing case for control
~asures in enclosed environments. Chest. 8d(1):90-5. 1983 Ju]
Adult
CarbonMonoxide C~rdiovascular Diseases: c ~ i c a t i o n s Female H u m a n "Legislation • " : e i o ae
Chil
C h i l d , Preschool
Lung Nico Resp S.~k, Toba, Unit Enter RE
W
Set A Set g Set C Set D Set E
-
TObacco Smoke P o l l u t i o n Legislation (581 A AND B (1) Lancet (DgDS) ~ti-lnfective Agents
{gO)
(2D)
Display Papers in SET? D
Combination of j o u r n a l t i t l e and Subject
AND also in SET? E AND also in SET?
i _
Reference 2 of 4 Greenwood D Laveriek A A c t i v i t i e s of newer qutnolones a g a i n s t L e g i o n e l l a group organisms Lancet. Z(8344):279-B0. 1983 dul 30
letter
Anti-lnfectlve Agents: pharmacodynamic%* Drug Resistance, Microbial Leglonella: classification, drug effects" Nalldixi¢ Acid: analogs & derivatives', pharmacodynamies Qulnolines: 9harmaeodynamics" Enter RETURNto continue, P to print. D to go back, Q to qult
DETUR~/P/BIQ
Database development, equipment, computer storage, and online access are underwritten by the library. Because the major computer costs are absorbed by the library's internal automated system, it is difficult to separate some cost factors. Georgetown decided to make use of the flatfee option for the NLM tapes. Smaller versions at a reduced fee are available. The estimated costs of creating and maintaining the database are given in table 1 as a guide. These figures do not include the cost of the miniMEDLINE software applications programs, nor the cost of the hardware required to replicate the system. Table 1 : Annual Cost of Database Maintenance
Annual NLM fee for subset tapes Ongoing programming Preloading tapes Disk storage* Supplies Staff time (approximately 5 percent)*
Figure 3: Two-Step Approaches to Developing Sets for a Bibliography.
References i
$14,600
Clague RB Moore LJ IgG and IgM antibody to native type II collagen in rheumatoid erthrltls serum and synovlal f l u i d . . . ARTHRITIS RHEUM. 27(12):1370-7. 1984 Dec i Figure 4: Combining Terms by Building Sets.
the names if he was uncertain of the initials. These names would become Set B. The menu returns to the screen automatically to progress to the second step, the displaying of options. In this example, the seventh option (combine the references from both Set A and Set B) is selected; the match results in Set C. The references in Set C are then displayed. As the user reviews each citation appearing on the screen, he also has the option of retrieving the abstract. The user can select which citations to print; at
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i
Set A - Arthritis, Rheumatoid (753) Set B - MOORE L... (15) Set C - A AND B (1) Printout of References selected from set C Arthritis Rheum
38
$10,000 2,500 600 xxx 300
SUMMER AND FALL 1986
(* Costs and salaries vary) System Use The miniMEDLINE SYSTEM has been well received by students and the faculty. Terminals, available throughout the library, are in high demand. The miniMEDLINE SYSTEM facilitates users' teaching themselves; still, under the tutelage of reference librarians, students, and faculty members are quickly developing sound information-seeking skills and a good comprehension of techniques for making use of the system's storage and retrieval capabilities (by using Boolean logic, for instance). The degree of sophistication patrons exhibit when using miniMEDLINE varies enormously. The analysis of data collected on the number of searches, types of users, options selected, time spent, and searches printed reveals some trends in the behavior of users during the past two years. (See table
2.) The statistical data show that over 36,000
Table 2: Statistical Data --
System Use
1-- Searches 2. Users (students, reslaents, faculty) 3. Time Spent (hours) Total Time (minutes) Average Time (minutes) 4. References Printed 5. Average References Displayed Average References Printed
7/836/84
7/846/85
2-Yr~ ' Total
16,897
19,142
36,039
2,311 3,518 211,098
2,549 3,645 218,684
4,860 7,163 429,782
12 99,662
11 150,351
11.5 250,013
42
53
47
6
8
7
searches were conducted in the most recent twoyear period. This represents almost five times the average number of MEDLINE searches conducted by the librarians. The 7,163 hours of computer "connect time," at $22 per hour, would have cost over $150,000 on MEDLINE. Because the miniMEDLINE SYSTEM runs at 9,600-baud, the average time spent per search is only eleven minutes. As noted above, users are able to refine their own searches quickly and print only those references they need. (See table 3.) Table 3: Analysis of Retrieval
Search Options Author Title Journal Subject
7/836/84 1,070 602 1,275 21,556
7/846/85 6,502 4,663 1,591 19,770
2-Yr. Total 7,572 5,265 2,866 41,326
Display Options Option 5 Single sets Option 6 Two or more sets (Boolean "or') Option 7 Combination of sets (Boolean "and")
21,045
25,876
46,921
11,105
14,719
25,824
1,454
1,711
3,165
These data support the theory that novices feel more comfortable working with searches for single subjects. More sophisticated users have learned to manipulate sets using the Boolean OR, but these patrons represent only 31 percent of the total number of users. Only 5 percent have learned to apply the more complex strategy of using Boolean AND logic. If a comparison is made between the two years, the figures indicate a slight increase in the sophistication of users. In the first year, 63 percent of the users retrieved single sets, while 33 Percent used Boolean OR, and 4 percent used Boo-
lean AND. In contrast, in the second year, the figures indicate a gradual shift from single sets (61 percent) to retrieval using Boolean OR (35 percent) and Boolean AND (7 percent).
CONCLUSION The miniMEDLINE SYSTEM is popular at Georgetown and is becoming successful nationally. Other medical libraries are already beginning to adopt the concept of a collection-oriented MEDLINE database with value-added, user-friendly features. Some libraries are designing their own search systems, a few are working with commercial vendors, and others are acquiring the miniMEDLINE software from Georgetown. The university provides assistance in implementing and maintaining the system, and trains the staffs of user institutions. The original miniMEDLINE SYSTEM is continually being enhanced. Georgetown has made numerous annual modifications. The NLM has permitted a feasibility study to test miniMEDLINE on CD-ROM. Indirectly, this has resulted in a cooperative project between Georgetown University, Digital Equipment Corporation, and the NLM in which research is being conducted using a new technology in a library setting. The system is currently undergoing testing. If successful, the results of this partnership can be shared with other libraries.
NOTES 1. N.C. Broering, "The miniMEDLINE SYSTEM: A Library-Based End-User Search System," Bulletin of the Medical Library Association 73 (April 1985): 138-145. 2. Georgetown University Medical Center, "Library Information System Manual" (Georgetown University, Dahlgren Memorial Library, 1984), G1. 3. "CD Reader and CD ROM: A Revolution in Information Delivery" (brochure, Digital Equipment Corporation, 1985). 4. N.C. Broering, "The Georgetown University Library Information System (LIS): A MinicomputerBased Integrated Library System," Bulletin of the Medical Library Association 71 (July 1983): 317323. 5. A.E. Zuckerman, "Bibliographic Systems," in Computers and Libraries." A Management Seminar, ed. N.C. Broering et al (Washington, DC: Georgetown University Medical Center, 1982): 52-58. @
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