Education And Debate

ABC of Medical Computing: THE INTERNET

BMJ 1995; 311 doi: (Published 12 August 1995) Cite this as: BMJ 1995;311:440
  1. Andrew Millman,
  2. Nicholas Lee,
  3. Kevin Kealy

    The Internet is a huge network of computers that spans the globe. It originated in the late 1960s from an American military project which was intended to provide reliable communications in the event of a nuclear war. The network started with just four computers but grew rapidly over the next few years. An estimated 40 million computers are now connected to it, and this number is growing by about 10% each year. Although access was originally restricted to government departments and organisations such as universities, the Internet has recently been opened up to everybody. It is now used by people and organisations from all walks of life including commercial organisations, university departments, hospitals, and medical schools, as well as agrowing number of individual users dialling in from home.

    What does it do?

    The Internet is best regarded as a framework which allows the free exchange of information between computers. With new services and users connecting to the network every day, it is becoming increasingly valuable as an information resource and communications superhighway. Among other things, it is now possible to access thousands of databases at universities and other research centres all over the world, read electronic journals, view and buy products from numerous companies, exchange news and views on a wide range of specialist subjects, and send virtually instantaneous electronic mail to any organisation, company, or individual connected to the internet.

    Services available on theInternet

    • Information browsingCommercialNon-commercial

    • Electronic mail (email)

    • File transfer

    • Newsgroups

    How do I get on to the Internet?

    Accessing the Internet is very easy. You need a computer and a modem connected to a telephone line, and you will also need to contact an Internet service provider who will supply you with suitable software to load on to your computer, an Internet telephone number and password, an email address, and access to a help desk. Good software will store the telephone number of your service provider and your password during installation, and after that clicking on the connect button will automatically log you on to the net within a few seconds.

    When selecting a service provider you should consider not only the initial connection charge and monthly service costs, but also the distance to the nearest access point. You may be able to find a local service provider but, if not, several of the larger companies offer a range of access points (called virtual points of presence or POPs) all over the country. Long distance telephone calls add considerably to the cost of using the service. One of the greatest advantages of the Internet is that connection to any other computer, whether it is just down the road or on the other side of the world, should cost no more than a local phone call.


    An integrated Internet access package

    What to do when connected

    Once you have connected to the Internet you normally see the service provider's home page, which is a like a menu. The page gives information about how to use and get the most from the Internet. It will also guide you towards search facilities which scan the Internet for the information or products that you require and FTP (file transfer protocol) sites which store programs, pictures, sound, and video files that you can download for use on your own computer.

    The worldwide web (often referred to as WWW) is the most recent and interesting development on the Internet. It offers user friendly access to millions of pages of information on computers all over the world. To access the web you need a graphical browsing program (running under Windows, Macintosh, or OS/2). A program such as Netscape or Mosaic should be supplied as part of the package you purchase from the Internet service provider.


    Accessing a typical worldwide web page with the Netscape browser.

    Navigating the worldwide web

    Almost every page on the web has a number of hypertext links to other pages on the same computer or to pages stored on another computer (often on the other side of the world). These appear as coloured text and are the easiest way to navigate around the Internet. Simply clicking on the text with the mouse takes you to the relevant page within a few seconds. Browsing programs keep a temporary list of the pages that you have viewed during a session, and it is easy to move backwards or forwards through the list one page at a time. You can also get a pull down list of the pages that have been accessed and go directly to any given page. Particularly useful pages can be tagged with a permanent bookmark, which allows you to return to that page at any time in the future.


    Hypertext links are the easiest way to navigate the worldwide web.

    Uniform resource locator (URL)

    All web sites have an Internet address termed a uniform resource locator (URL). If you know the address for a particular web site, type it into the location box of your browser and you will automatically be connected to the correct site. The box gives some useful addresses that you could use as a starting point for exploring the Internet using hypertext links and bookmarks. You should, however, bear in mind that the Internet is constantly evolving and that addresses do change sometimes. Up to date list of addresses can be found in Internet magazines and increasingly in medical journals.

    Useful worldwide web addresses

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    Searching for information

    Because the Internet is so large it is important to have an efficient way of finding the information that you need. Fortunately, there are now several computers dedicated to indexing the information scattered all over the world. These computers can easily be searched for any word or phrase, university, company, or subject.

    Popular search engines include InfoSeek ( or Lycos ( These services offer the casual user a limited number of hits free of charge, but comprehensive results are available only to subscribers. Alternatively, you can use Yahoo (, which displays information in the form of a tree, has extensive records of health care resources, and is entirely free. All the search systems present results in hypertext format. It is therefore very simple to browse through the search results to find exactly what you want.


    Search engines will help you find what you need

    Electronic mail

    Email ranks alongside the worldwide web as one of the main attractions of the Internet. It allows you to send messages to other people in just a few seconds even if they are thousands of miles away. You pay only the cost of the telephone call to your service provider. The same message can just as easily be broadcast to a group of people. In addition to simple text, you can send documents, graphics, sound files, and even programs, although you will need additional software (UU encoding/decoding) to do this. You could, for example, send a note to a colleague asking for an opinion on a clinical photograph, research data in a spreadsheet, or even a set of slides for a lecture.


    Using email software to send a message

    Although you can write messages while connected to the Internet, it is more cost effective to write your messages before connection (off line). Your service provider will usually supply you with a program to do this. The program puts all your outgoing mail into a packet which is automatically dispatched the next time you dial into the Internet, while messages addressed to you are simultaneously delivered to your computer.


    How an email address is derived

    It is not uncommon to get a reply to an email message within a few minutes. If an email message cannot be delivered for any reason (for example, an incorrect email address) the system will usually let you know, but there is no reliable way of telling if someone has not dialled in to collect the message.

    Commercial services

    Companies and organisations are increasingly realising that the Internet offers an unrivalled opportunity to reach a global market. In most cases they offer information on and support for their products, but some are now offering items or services for sale. For example, you can look up flight information, book an airline ticket, and arrange hire car and hotel accommodation at any time of the day from the comfort of your own home. Secure systems which allow you to pay for these goods and services by credit card are being developed, but if they are not available it is best not to send credit card numbers across the net in case of interception. Some secure systems can be recognised by the use of https:// at the beginning of the address or your browser may display a helpful icon such as a key.


    The BBC's web pages provide a wealth of information about its programmes.

    Transferring files

    You can use the Internet to access computers that are dedicated to storing programs, pictures, sound, and video as well as text files. Some of these sites are open only to authorised users, but others allow anyone to dial in, browse, and download anything on offer. These are called anonymous FTP sites. One of the largest FTP sites in Britain is at Imperial College, London ( To access the site simply type the address into the location box. Don't expect to find commercial programs, but there are extensive collections of shareware as well as many programs in the public domain which can all be obtained for the price of a local phone call.


    Imperial College's home page gives you access to a wide range of programs and shareware


    The Internet also lets you exchange news and views on a variety of subjects in forums called newsgroups. There are a growing number of groups dedicated to medical topics. Although they are of most interest to specialists, they are all open to the general public, and it is not uncommon to see a question posed by a patient with a problem. People using the system post messages or questions to a 24 hour global audience and can therefore expect several replies within a very short time. A list of current medical newsgroups is maintained at Johns Hopkins University ( Some of these groups are very active, with hundreds of new messages being posted every day. If you intend to regularly read and reply to these messages it is a good idea to invest in a very fast modem.


    Johns Hopkins medical newsgroup list.

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    The first figure is reproduced with permission of Kevin Hughes. All copyrights acknowledged.

    Andrew Millman is occupational physician, Gloucestershire Royal Hospital, Gloucester; Nicholas Lee is consultant ophthalmologist, Western Eye and Hillingdon Hospitals, London; and Kevin Kealy is an Internet consultant, Unipalm PIPEX.

    The ABC of Medical Computing is edited by Nicholas Lee and Andrew Millman.

    List of United Kingdom service

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