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Built on top of Internet are a series of other protocols which allow electronic mail, remote login, file transfer, gopher, and finally the World Wide Web. The World Wide Web protocol permits use of most of the other functions of Internet, in a fashion which is understandable to the non computer specialist. This workshop will only deal with the World Wide Web.
At home or at Internet deficient facilities, you will need to connect to an Internet provider yourself. The on-line services are beginning to offer more and more of the Internet capabilities to their users, and there are other services which will connect you directly to the Internet. Your personal computer can be connected over a regular telephone line using a modem and either the Serial-Line Internet Protocol (SLIP) or the Point-to-Point Protocol (PPP). In order to make use of the multimedia capabilities, a 28,800 bit-per-second modem is desirable. If your local telephone exchange permits, an even faster connection can be made with ISDN, although ISDN has been slow penetrating to the end user. The cable companies, the telephone company, and even power utilities starting to provide internet connection using RF-modem. An RF-modem connects over an unused television channel at speeds of about 10 megabits-per-second. I have been connected to the internet via my local cable provider for over a year. Initially, we were beta testing the cable connection, but now connection is commercially available in my neighborhood.
You should not have to worry too much about these details. You should be able to purchase bundled hardware, software, and Internet provider access which is reasonably easily installed on your personal computer. The key issues are what services are provided and how fast is the connection. One decision you will need to make is whether to use an on-line service or a direct internet connection. The on-line services provide added value services and are often the easiest to set up, but usually are more expensive and have some limitations. You should demand Internet mail and a full function World Wide Web browser including network news and file transfer (ftp) capabilities. The fastest connection is a direct connection (e.g. ethernet) by Information Services at your hospital; an RF-modem from your cable company may be about the same speed; next best is ISDN; the slowest acceptable connection is a 28,800 bit-per-second modem over standard telephone lines.
How do you get started? The client program on your computer might have a convenient method of getting started. By clicking on a button, you might go to some home page which then points to other interesting locations, or a home page may come up automatically. Unfortunately, that home page may not be of most interest to you. Instead, it may be more useful for you to start at the RSNA or the SNM home page. In order to do that, you need to type in a reasonable long Uniform Resource Locator (URL), e.g. "http://www.rsna.org/" or "http://www.snm.org/". Once you arrive at a page you find interesting, then you can leave a bookmark at that page so that next time you can go back to that location without typing in the URL.
The advanced user can often guess the URL of major organizations. The last three letters are "edu" for educational organizations, "com" for commercial organizations, and "org" for societies and organizations. The first three letters of the major World Wide Web site for an organization are often "www". A good guess for the home page of a University is "http://www.name.edu/", where name is the common name or acronym for the University. Similarly, a good guess for the home page of a company is "http://www.name.com/", where name is the common name of the company.
How do you keep from getting lost? The short answer to this question is practice. The World Wide Web is a web; it is not organized. You can get lost easily. You can find something which is very interesting, and then not remember how to get back there. Since authors tend to link to related topics, you will find there are a lot of circular paths. There are some tricks. When you find something useful, leave a bookmark so you can get there again. The hyperlinks usually change color once you have been to a particular location; the color clue can keep you from going in circles. If your lucky, you can find a home page organized by someone with similar interests to your own. That page will often serve as a good starting point. The key feature, is that after you get used to surfing, it becomes much more natural.
How do you find resources? Indexing is one of the features of the Web which is in evolution. The short answer to the question is that there is not a single good way to find resources. There are, however, some tricks which help. Often if you have found a good starting point, that is the best place to look for related topics. There are some indexes and some "search engines" which can lead you to a large number of resources. "Yahoo" is a well known index which can be reached from Netscape"s home page. Yahoo has pointers to other well known search engines such as Alta Vista, which is a massive resource. I find Yahoo very useful for general topics - it has both a tree structured index and a word search. Alta Vista often overwhelms you with references on general topics, but when I want to find a very specific topic, Alta Vista is most likely to have a reference. I have listed some search engines in my own list of interesting URLs "http://www.med.harvard.edu/JPNM/InterestingURLs.html". To use a search engine, you often type one or more keywords into a form, and then the search engine returns a list of locations on the Internet which contain those words. Look at the instructions, since the syntax may not be obvious.
2. Parker JA: Access to the internet / learning resources. Clinical Nuclear Medicine: 1996 http://www.med.harvard.edu/JPNM/Lectures/Internet/ClinNucMed96.html.
3. Barbaras L, Parker JA, Donohoe KJ, Kolodny GM: The all-digital department moves to the web. RSNAej July/Ausust, 1996,
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