Journal of the American Medical lnformatics Association Volume 3 Number 1 Jan / Feb 1996 .:.~.~.:.~.~,:.~.~ .:::::::*#$J r.:.::::s.::::::::::::. :.:~:.:.:.:.:.:.:.:.:::.:::.:::::::y::g$ ,gg$$y,< ;:$$$$;$ t.:.:.>:..:.:.:,:.:.:.:.A..... .,...,.,.,.,., ::::::.:.:.~::::::::::::: ~:::::::::::::::::::::.:~.::::::::::g::::: i?.~.%...A.. ,:‘x,:.:::.::::::::::::::::, ::::::::::::x: The ~~~~~~~~~:, ,#$J$$ :g:::*g. ~~~,~,~~ ~~ :g$$p :.:.:.:.&:: .. ‘..,:.~.~.~. ::::::::::::::::z .Hg$ :::$$:.:.:.:;. :sE?r:: sjfzz W$ $.$gZ ‘::::::::::$f:?, ..i. _.,..,...., . I .,._,.,,,.,._ .:.:.~.~ :::.: m :~:~:~:~:::~:~:~~.gx:z:y: ,,.,.g:$;:g$;, $~:$:~.y::~,.,.,_.,...,. ,$y$$$. g i.:.:.:.:.:.:.~.:.:.:.:.:.:.:.:.:,.., .. ...) ..,. .~l.....:.>:.:.;: ::::::::::x: $;$g$~ :.:.’ ::::;::::::::::> :.:.:.:.:.:<.:.:. :.:.:.:.:.:.:.:....w.. :.:.:,:,~, =I; $$$g:@ ::::::::::>:::: ::::::::::::::::: :~.&:.:p:.:.:.. ::::::::::::::::: :::::::::::::::::: .. ..cT...V.V .,.,.,...,.,., ::::::::::::::::: ~~:~:~:::~:;:;:~:’gg$f:$ s$#:E .:.x.:.:.:.::::::.,::~:::: .:.:.:.:.:+:.>,..:::::::::::::::::’ :~~~:~~~:::::::::~,: .::::::::$g ::::::::::x.:. .:,:.:.:,~:.:.:. ,~g:“““.L ,:~:~~ ,~:::~:~::i:::$~:, :::::::::+:.:., .:.:.:.:.;,>;:.!zsg3 ::::::::y,::: ,+:,~.~.~.~.~.~:,:.:.~.~.~.:.~.~ .. .. .. .. .. f j ‘.‘.::::;:#~:g:~ ,~~~~>~ ‘;g$gE; :.:~~~~~,:,:~:~::My:: ;:mr gg$$$ .g#@. .. .. Review n The World Wide Web: A Review of an Emerging Internet-based Technology for the Distribution of * Biomedical Information ::::~:::::::::::~::::::::::::9::::::::::::~::::::::::::::::::::::~::::::::::::::::::::~::::::~::::::::::::::::::::::::::::::::::::::::::::~::::::::::::::::::~:~::::~:::~,::::::::::::::~::~::~:::::::::: HENRY J. LOWE, MD, EDWARD C. LoM.~, MLS, STACEY E. POLONKEY Abstract The Internetis rapidly evolving from a resource used primarily by the research community to a true global information network offering a wide range of databases and services. This evolution presents many opportunities for improved access to biomedical information, but Internet-based resources have often been difficult for the non-expert to develop and use. The World Wide Web (WWW) supports an inexpensive, easy-to-use, cross-platform, graphic interface to the Internet that may radically alter the way we retrieve and disseminate medical data. This paper summarizes the Internet and hypertext origins of the WWW, reviews WWW-specific technologies, and describes current and future applications of this technology in medicine and medical informatics. The paper also includes an appendix of useful biomedical WWW servers. n JAMIA. 1996;3:1-14. The Internet is rapidly evolving from a resource used computers (PCs), and the development of easy-to- primarily by the research community to a true global use communication software. Media coverage of the information network offering, in many cases, unre- Internet has also resulted in more widespread aware- stricted access to a wide range of databases and ser- ness of how this global data network can enhance vices. This rapid growth in Internet use is being driven business, science, and education. In turn, this aware- by a number of factors, including- increasing “com- ness has produced a significant demand for afford- puter literacy,” availability of affordable personal able commercial services providing Internet access to those outside of the scientific and educational com- munities. Affiliation of the authors: Section of Medical Informatics, Univer- sity of Pittsburgh, Pittsburgh, PA. One of the most significant developments driving this growth has been the emergence of the World Dr. Lowe and Ms. Polonkey are supported by National Library of Medicine Biomedical Applications of High Performance Comput- Wide Web (WWW) as a technology for accessing the ing and Communications (HPCC) Contract number NOI-LM4- vast array of resources available on the Internet. The ‘3507; Mr. Lomax is supported by National Library of Medicine WWW provides an easy-to-use, inexpensive, cross- Medical lnformatics Training Grant number 5-T15-LM070-59. platform, graphic interface that allows even a casual Correspondence and reprints: Henry J. Lowe, MD, Section of user to successfully navigate the complex web of linked Medical Informatics, University of Pittsburgh, B50A Lothrop Hall, computer systems that is the Internet. The impact of 190 Lothrop Street, Pittsburgh, PA 15261. e-mail: [email protected]. WWW technology on biomedicine may be significant. nih.gov The ease of creating and accessing Internet-based Received for publication: 3/28/95; accepted for publication: 9/12/95. WWW servers combined with the platform-indepen- LOWE ET AL., World Wide Web Review dent capabilities of this technology will likely result Hypertext:A Brief Introduction in the widespread availability of clinical, research, and educational resources on the Internet. This paper The WWW is essentially a network-based, distributed provides an overview of the history and technology hypertext system. Initially envisioned by Bush,’ fur- of the WWW, describes a number of existing biomed- ther described by Engelbart,2 and defined by Nel- ical WWW servers, and discusses future medical ap- son,l the conceptual model underlying computer-me- plications of this important technology. In addition, diated hypertext in modern information systems is a we have included an appendix containing pointers simple one. Links to component objects or nodes to a variety of useful WWW resources and sites. (e.g., text, images, sound) are embedded in a given document or set of documents. These nodes may be linked to associated nodes to form a database by way The Internet of a set of links. The logical extension of this model is that of a “meta-document” that would essentially The Internet, as we know it, was initially conceived be a hypermedia database of hypertext documents. by Paul Baran, an employee of the Rand Corporation. This model allows the user to easily navigate an ar- First published in a series of Rand reports in the early bitrary set of links between nodes in a document or 196Os, Baran’s ideas would become realized with the database based on the user’s information needs rather creation of the Advanced Research Projects Agency than the fixed data linkages defined in traditional Network (ARPANET) in 1968.is The introduction of information retrieval systems. the Transmission Control Protocol/Internet Protocol In a definitive article on the subject, Conklin suggests (TCP/IP) in the early 1970s allowed for interopera- the following four broad applications for computer- bility between heterogeneous computer systems, end- based hypertext systems,‘O and potentially WWW, to-end communication across a multitude of diverse which are relevant to medical practice and medical networks, and robust, automatic handling of data informatics: link failures. The original aim of the ARPANET was to provide n macru literary stystems: systems and technology that remote access to distant computers, remote file shar- ” I ing, and the expansion of computer science research support large on-line libraries with computer me- through resource sharing. The ARPANET was dis- diated interdocument links (for example, network- solved in 1990, having evolved into the Internet, a oriented publishing, reading, criticism, and collab- collection of interconnected networks that span the oration in document creation). globe. The Internet has become the fastest-growing problem exploration systems: tools to support early electronic network in the world. Current host growth unstructured thinking on a given problem (for ex- rates are estimated at 10% per month, with network ample, early authoring, outlining, problem solv- traffic doubling annually.‘j7 TCP/IP, the principal ing, programming, and design). communications protocol of the Internet, has been widely accepted. Until recently, the U.S. portion of structured browsing systems: small-scale teaching, the Internet was funded, in part, by the federal gov- reference, and public information systems similar ernment. The National Information Infrastructure (NII) in design and function to macro literary systems. initiative sponsored by the federal government has In these systems, ease of use is a critical design redefined this funding model and replaced it with component. private-sector investment and network management. n general hypertext systems: general-purpose systems A significant recent development has been the wide- for reading, writing, collaboration, etc., designed spread adoption of the WWW,68 and, especially, a to allow experimentation with a range of hypertext number of easy-to-use browsers, which offers a graphic applications. user interface to the Internet. This paper focuses on the WWW and its potential in clinical information Macro literary systems were among the first attempts dissemination and retrieval. For a more general treat- at computer-based hypertext systems. Bush’s vision- ment of the Internet and its application in medicine, ary concept of the “memex,“’ a machine/model for the reader may wish to consult a number of recent browsing and note creation in an environment of papers on the subject. 3~* WWW technology, based extensive on-line text and graphics, was the under- in part on the hypertext concept, may be a significant lying impetus for these systems. catalyst in the transformation of the Internet from a research tool to a true global information network. Among the major efforts in this arena include the work of Engelbart, the creator of the mouse, and his The World Wide Web NLS/AUGMENT system’; Nelson and the Xanadu project”;