The World Wide Web (hereafter the Web) is a global hyper-media system which offers access to documents distributed all over the world. It was born at CERN, the Swiss research institution, which was dependent on the exchange of information among research colleagues. It has now grown into a global network of documents consisting of text, images, graphics, sound and video. The number of information providers for the Web has increased very speedily. Typical suppliers are universities/colleges, public institutions and businesses, but schools and private individuals are also contributing. A growing number of commercial enterprises now offer their wares or services for sale on the Internet.
The World Wide Web is an information system based on hypertext links. Hypertext documents are linked via selected words in the text itself. By clicking on these words, which are printed in bold or underlined, you may effortlessly "jump" from one document to another. These "jumps" may be to other parts of the same document on the same computer, or may be to another computer halfway round the world. There is no difference for the user - if you disregard speed: it may take somewhat longer to download a document if it resides on a distant computer.
The figure above shows an example of a Web structure. The document at the top in the figure may be a document you have made to explain WWW. From individual words in this text (underlined) you may create links to information which is stored on other computers anywhere in the world. These links provide more information about the word in question. The figure above shows only text documents, but this could equally well be graphics, images, sound and video.
The Web is a global hypertext system. Navigating this system is often called surfing on the Internet.
The Web is a client-server system where most users retrieve information using a client application on their own PC. Examples of client software are Netscape, Mosaic, Cello and Lynx. The most extensively used client application by far is Netscape, which comes in versions for MS Windows, Macintosh and X Windows systems.
Information suppliers for the Web use a so-called Web server. Some information suppliers use a separate computer as their Web server, while others rent space on existing Web servers.
Below is an example of Web pages used by NITOL courses given by
the Department of Information Technology, The College of Sør-Trøndelag
County. On the left is the main page, on the right the page which
appears if you click your mouse on the hypertext word "INNGANG
TIL FAGENE" [ENTER HERE FOR SUBJECTS]. On the page on the
right you can click on each individual subject. You may then
read lessons onscreen, or download them to your own PC to be read
there or printed on paper.
You can go directly to the website by clicking on the picture.
A number of you will already be familiar with electronic mail, and some will also have written or read e-mail from a PC connected to a LAN. For many people, however, e-mail only means sending letters to colleagues on the same LAN.
If your PC is connected to the Internet, you may send e-mail all over the world, not only within the world of the Internet, but also to collaborating systems, for instance X.400-addresses.
Using an e-mail application on your PC you may write your message in a text editor, and then transmit it to a destination where the receiver may read it on his/her PC seconds after it was sent. The requirement, however, is that the PC has e-mail software and that these PCs are linked to a network, and that the PC is connected to the Internet if a letter is to be sent to the world beyond your LAN.
The first e-mail software was for simple message exchange between two persons. Later applications have been given many new capabilities, such as sending mail to several addresses at once, sending messages which include sound, video and images, forwarding letters, storing and organising letters in folders etc.
This means that being skilled in the possibilities and use of modern mail systems is essential.
E-mail combines the best features of ordinary mail and the telephone, allowing huge documents which include images and graphics to be sent at speeds comparable to that of the telephone. In contrast to the telephone, e-mail has the added advantage that the addressee does not have to be present when you want to communicate. The message can simply be put in the mailbox of the recipient.
Everyone using e-mail needs a personal mailbox to receive electronic letters. This mailbox is really a storage area on a computer harddisk which also functions as a posting computer. This computer cannot be an ordinary PC which is turned on and off every day. The posting computer is on night and day, as mail might arrive at any time.
Arriving letters are automatically stored in your mailbox. This is your private mailbox, and only you may access it. To read your mail you need e-mail software, for example Eudora, which you start on your PC. Using Eudora you connect to your mailbox so you can move the letters to your local PC to read them and store them in folders.
Each mailbox also has a mailing address, just the same as your mailbox outside your house.
To send a letter you need to use an application such as Eudora. First you must write the letter. Then you fill in the address field and a subject field, all of this using the same software.
The mail application can be set up so it will alert you when new letters arrive, either as a sound signal or a pop-up message box.
Then you use your mail application to fetch the message from the mailbox and read it. The message tells you who sent it, when it was sent and of course there is the content of the message itself.
Having read the message you may do one of several things: You may respond to the message immediately by choosing a reply function in the mail application, you may store the message in a folder or you may delete the message.
Electronic mail messages have a number of things in common with the usual message forms you use around the office. They include an addressee field, fields for time, date and subject, and the message text.
An electronic letter contains a "head" and a "body" as shown in the figure below. The head contains several fields with important information both for the receiver but also for the mailing system. The most common fields are From, To, Copy To (also called Cc), Date and Subject. Each of these fields contains information filled in by the user or automatically by the mailing system.
The user fills in data in the To, Cc and Subject fields, while the mailing system automatically fills in the fields From, Date, in addition to some others which the user does not see.
One of the major advantages of electronic mail is the option of sending the same letter to many persons at once. There is no need to make many copies of the letter beforehand. The only thing required is to insert the names of several persons separated by commas in the To: field. This can also be done in the Copy To field.
If you think there are too many addresses to put in the To field, the alternative is to define so-called alias lists. These are lists of e-mail addresses which you may operate under just one name. For example, during a project you might need to send the same letter to all project members at the same time. Then you define an alias using a name such as project-members, which is a list containing the e-mail addresses of all project members.
project-members = per@idb.hist.no
turid@idb.hist.no
kari@telenor.no
vidar@iff.unit.no
stig@cx.telepost.no
The letter is sent to all members on the list if you put project-members in the To field.
Alias lists may be defined by system supervisors or by the individual user. Alias lists which all employees need are placed on the mail server available for everybody. In addition to these joint alias lists, users may define their own private alias lists on their own PCs. These will not be available to others.
Electronic mail is not only used to send regular text messages. A recent extension is called MIME (Multipurpose Internet Mail Extensions). Using MIME you may append any file to your e-mail message as an attachment. This attachment may be a word-processing file (WordPerfect, Word), a spreadsheet file, a sound file, a picture, a video clip etc.
If both the sender and the receiver have e-mail applications which support the MIME standard, any file may be exchanged. Do remember, though, that the receiver requires a copy of the application used to create the file to read the attachment in question.
As all other Internet services e-mail functions as a client-server system. Two applications co-operate to transfer the letter from the sending to the receiving computer.
From your PC which runs the e-mail application (for example Eudora), the letter is initially sent to the mail server you are connected to. The letter is then processed by a so-called mail transfer application which transmits it from the sender's mail server to the addressee's mail server somewhere on the Internet. There the letter is placed in the addressee's mailbox.
To ensure the safe arrival at the receiving server the transferring server always retains a copy of the letter. If the receiving computer is unavailable, the letter will be stored on the sending server for a period of time. The mail transfer application will attempt to send the message at regular intervals, as the receiving server may be off-line only temporarily. If no contact has been established after a certain time interval, the letter will be returned to the sender along with an explanation as to why the letter did not arrive at its destination.
The letter may also be returned if the receiver indicated in the To field does not exist. In such cases the letter will returned in minutes, the sender being stated as MAILER-DAEMON.
The figure above applies to PCs connected to a LAN. Modem users dial into the mail server via telephone lines and their modem. Users who alternate between logging in via the LAN and a modem should use the same mailbox every time, the one they have on their LAN.
Users with no mailbox in a LAN have their mailbox on the mail server of their Internet provider.
All e-mail addresses on the Internet must be unique so that there is no conflict as to who should receive an e-mail message. Hence the address must include a description of the receiver both by name and by geographical/organisational location.
Internet addresses consist of two parts separated by the @ character. This character is usually read as "at". In front of the @ we find a designation of the person. On the other side of the @ there is a so-called domain name, describing the geographical or organisational setting.
Some examples of domain names:
idb.hist.no -The Department of Informatics, The College of Sør-Trøndelag
hitra.vgs.no -Hitra upper secondary school
tv2.no -TV2
bilkent.edu.tr -Bilkent University, Ankara
ktu.lt -Kaunas University of Technology, Lithuania
inf.utfsm.cl -Federico Santa Maria University, Chile
The final part of the domain name usually indicates the country of origin by means of standardised country codes. All domains in Norway have "no" as their final part. Sweden uses "se", France "fr" etc. There are some exceptions to this, where the last part is not a country code, but rather "com" for commercial, "mil" for military, "edu" for educational, "gov" for government, in addition to some other varieties.
If all organisations were allowed to choose their domain name freely, there would be any number of variations and this would make it impossible to have a system for domain naming. UNINETT manages all domains in Norway so that the domain names for different organisations follow a logical model (all upper secondary schools follow the pattern of school-name.vgs.no, all primary schools have school-name.vgs.county.no). All sub-domains under .no must therefore be approved by UNINETT.
The main principle is that the user name of the receiver will be placed before the @ in the address. The user name is the name used when logging onto the network. Such user names may be difficult to remember for other people because they commonly consist of initials or fragments of the user's given name and/or surname.
Most modern e-mail servers therefore are equipped with a system permitting the use of a person's full given name and family name separated by a dot. This requires that the e-mail server has a list of full names, and which user names they correspond to. Let us assume that the e-mail server has access to the following information:
Grete.Andersen corresponds to gretea
Per.A.Olsen corresponds to perao
Per.Olsen corresponds to perao
Letters for Grete.Andersen will go to the mailbox of user gretea. Letters for Per.A.Olsen will go into the perao mailbox, as will mail sent to Per.Olsen.
Such an alias list also includes some names which are always required in a domain. For example, it must always be possible to send mail to postmaster@domains, as in postmaster@idb.hist.no, to reach the person in charge of the domain e-mail system.
The mail server alias list may also define an alternative name for a list of persons. At the Department of Technology, The College of Sør-Trøndelag, mail can be sent to students, employees or simply everybody.
Perhaps you do not know somebody's e-mail address? Try the X.500 catalogue which you will find in the main chapter «Katalogtjenester» [Catalogue Services] in this book.
The special Norwegian vowel characters æ, ø, å cannot be used in e-mail addresses. This precludes sending e-mail to Pål.Værnes@idb.hist.no. There is a standard for replacing these Norwegian special characters:
æ -> a ø -> o å -> a
This makes Pål Værnes' e-mail address the following:
Pal.Varnes@idb.hist.no
There are several ways to connect to the Internet, which will enable you to post messages to other persons also connected to the Internet. You may dial into the net via your phone and modem (typical home user) or you may connect to the Internet via the LAN at your workplace. In the following sections I shall try to address the needs of both user categories when explaining the methods of use. They may be different as a modem user is interested in keeping his telephone expenses to a minimum.
If your PC is on a LAN connected to the Internet you can send e-mail letters to any other Internet user in the world through your PC, and of course they can send e-mail to your mailbox located on one of the computers in your LAN. This computer is running day and night as mail might arrive at any time (from all corners of the world).
If you dial into the Internet using your phone and a modem you also need a mailbox. This cannot be on your local PC, as it is only intermittently connected to the Internet. Your mailbox may either reside on your workplace LAN or on a mail server operated by your Internet provider.
If you dial into the Internet via a modem you normally do this according to the following routine: You log in via the terminal server to your Internet service provider (for example UNINETT), and then you start your mail application. Your mail application contacts your mailbox computer, and transfers any new letters to your in-tray on your local PC. Then you disconnect, to read your letters off-line, since you will not want to pay the telephone company for telephone use while you read. You can also compose letters and reply to letters without going on-line. All out-going letters are placed in the out-tray by clicking the Queue button. This means that these letters are placed in a queue to be sent the next time you go on-line.
When you have finished composing and answering letters you connect to the mail server again. Letters in the out-tray are sent automatically when you have logged on.
If your PC is on a LAN you will usually have direct access to the Internet. This means that letters you write are sent immediately from the e-mail application (Eudora can be configured to send letters immediately or placed in a queue for later dispatch). You are immediately alerted to incoming mail. This is possible because you are on-line on the Internet. You do not have to dial in, as modem users must.
The description below applies to users connected to the Internet via a modem. It also applies to connecting via a LAN, more or less, the only difference is that LANs have a direct link to the mail server. However, the fact that everybody must have a mailbox on a mail server, and the requirement that you need to log on to this mail server are the same.
Users who connect to the Internet via a modem already have their own mailbox on one of the Internet provider's computers (for example UNINETT). The e-mail application which came bundled with the software delivered by the Internet provider will usually be configured so it automatically connects to the appropriate mail server. This computer can receive mail addressed to you day and night (just as with your home mailbox outside your door).
When you want to read your mail, you must turn on your PC, connect to the service by logging in, start your e-mail application, Eudora, and select the menu item File/Check Mail. Eudora opens your mailbox on the Internet provider's mail server and transfers all your mail to your PC.
Transmitting mail from the mailbox on the mail server requires that you log on to this particular computer. Therefore Eudora demands a password from you before mail can be collected. If you know your mailbox password, then there is no problem. If you are uncertain, you could try the same password you used when logging in via your modem and the TCP-man application.
Note! To save on telephone expenses you may now disconnect. Your mail is now stored locally on your PC and may be read using Eudora.
Electronic newsgroups or conferences are forums for discussions corresponding to newspaper «letters-to-the-editor" columns. Other readers may respond to messages by sending in their own articles for publication. In the newspaper a discussion on a given topic might carry on in the letters-to-the editor column for some time. There might also be parallel discussions on varying topics. The downside of this discussion forum is that often a week or more will pass between letters. The electronic version of this column is called a newsgroup, or an electronic meeting. To participate in discussions in electronic newsgroups you need a separate client application to read newsgroups. Such an application is called a news reader, and you must use it to connect to a server holding the newsgroups.
Using a news reader of this type you may read existing articles, and you may compose new articles. You may comment on existing articles or post concrete questions.
The advantage of this electronic version of the "Letters" column is speed. Your letters (often called messages or articles) become available to the other members of the newsgroup more or less instantly.
All the computers which support electronic conferences of this particular type (newsgroups) constitute a network which is called Usenet.
A popular and very common misconception is to regard the Usenet as a kind of physical electronic network. Usenet is a network of computers which carry newsgroups. These computers are called news servers. Everything written to a newsgroup is distributed to all computers within a given distribution area of Usenet. A number of groups are also distributed globally.
You will have set up your news-client application so it reads letters from a certain Usenet computer, preferably the one closest to you. Anybody with Internet access may in principle take part in this message exchange on Usenet.
Usenet is organised as a set of discussion groups where each group focuses on a specific topic of discussion. The figure below shows the organisation of Usenet and how messages are distributed from computer to computer. Each computer taking part receives new messages day and night. An article written by a person in Mexico may be read after only a few minutes in Norway by you or me.
Usenet is not governed or controlled by any one particular organisation rather it is a self-governing community.
There are some rules - written and unwritten - for behaviour on Usenet. All users understand that abiding by the rules is for everybody's common good, and this in fact works. However, it is no secret that some transgressions occur.
In principle anyone may establish a new group. Nevertheless, if the discussion in a group starts to branch off in some other direction, when for instance some participants start to discuss football while in a serious newsgroup on the UNIX operating system, then the time is ripe to establish a separate, in this case, football newsgroup. In other cases members might vote to establish a new group. Finally, any systems supervisor can establish new groups.
Usenet is operated by its users. Users themselves decide what should be allowed, and they "decide" the rules. This means that all users must exercise self-control. It is entirely possible that one user breaks the rules, and blatant and conscious examples of rules being broken will lead to a strong reproof from other users via messages to the newsgroups.
New users may of course stumble when they are new on the net. More experienced users will then often offer helpful advice. However, it must be emphasised that finding out how the news system works before you log on is a good idea, and it may be a good idea to read a newsgroup for a few weeks before you post your own messages.
BBS means "Bulletin Board System", and may well be familiar to many of you. What is the difference between a BBS and Usenet? A BBS is one computer containing an information database. Users of this BBS may log on to this computer using their telephone and modem. You will find various kinds of information on the BBS, mostly existing as regular files. Most BBSs also have some sort of discussion forum where BBS users may post discussion messages and other users may reply. New users may browse the discussion to find out what has been said, and they may offer their own opinions. Up to this point this appears to be quite similar to Usenet.
However, the essential difference between a BBS and Usenet is that discussion letters on the BBS remain on the one computer only, while a new letter on Usenet will promptly be distributed to all the computers in the network which subscribe to this discussion group. Usenet users do not have to log onto a particular computer, they read the letters on their local Usenet computer which is a receiver of all letters produced on the Usenet.
On Usenet a new letter in a discussion group is automatically distributed to all the other Usenet computers. On a BBS the letter stays on the one computer. Persons who wish to read the letter must log on to this particular computer.
To read news articles and write your own news articles you need a client application (a so-called news reader) which will connect you to the closest news server, and which gives you a simple and user-friendly interface to the newsgroups. In this section you will learn to use two news readers: 1) Trumpet News, 2) News Xpress. There will be more about these later in the lesson.
When the client application for reading newsgroups is started, you will always get a list of new, unread articles which have appeared since the last time you were in. Typical activities when using a news reader are reading articles, replying to messages, subscribing to new newsgroups and unsubscribing to newsgroups.
In this way you may read newsgroup articles at your leisure. While you are reading, new articles may be arriving. The most advanced news readers keep track of this and offer you the option of reading these without having to start the news reader first.
There is a total of about 8,000 newsgroups on Usenet. Approximately 4,000 of these are available in Norway. Most of the groups not available in Norway are specific to individual countries.
News groups are arranged hierarchically as main groups and subgroups. In the name of the groups each of the sub-groups is distinguished from the others by a dot. One example of such a newsgroup is
rec.music.folk
which contains hobby-based discussions on music with the sub-theme folk music (rec is short for recreational). Let us watch what is going on in this newsgroup just now (11 February 1995)!
At the top in the window you will find a listing of the letters found in this newsgroup in February 1995. At the bottom the content of one of these letters is shown (the one highlighted in the listing).
This is one example of a newsgroup. You may ask: Which other groups are there, and how do I subscribe? The answer will be given pretty soon.
The seven main groups of newsgroups are listed below. Each of these is divided into a number of subgroups etc.
comp Anything concerning computers, hardware and software news On Usenet, e.g. the newsgroup news.newusers.questions and news.announce.newusers. Read these if you are new on Usenet rec Hobbies, recreational activities sci Research and development soc Political issues talk Debates on controversial issues, e.g. religion misc Anything at all
These main groups circulate all over the world. Moreover, some alternative groups have been established, usually because of pressure from users when the debate in a group has turned in unexpected directions. Then new groups are established instead of having the original topic "drown" in a number of discussions branching off and away from the original topic.
One well-known alternative group is the alt group.
alt Contains groups which started as alternative ways of regarding things. Over time this main group has developed into a holding ground for all sorts of groups, comprising religion, sex,jokes and advice and hints on weddings.
Within each country there are also separate newsgroups. In Norway all of these start with the country code for Norway, which is "no" and other countries, as we have seen, will have their corresponding codes. Examples of such newsgroups in Norway are:
no.film no.litteratur (literature) no.jus (law) no.uninett.skole (school) no.uninett.hjelp (help)
Below is an extract of a list of the approximately 4,000 newsgroups available in Norway.
alt.architecture alt.atheism alt.atheism.moderated alt.drugs.caffeine alt.music.prince alt.music.progressive alt.music.queen alt.religion.scientolog alt.sports.baseball.chicago-cubs alt.sports.baseball.cinci-reds alt.tv.seinfeld no.general no.uninett.diverse no.alt.radio-tv.irma-1000 comp.editors comp.human-factors comp.infosystems.gopher comp.os.ms-windows.programmer.memory comp.os.os2.multimedia comp.protocols.iso.x400 comp.publish.cdrom.software soc.couples.intercultural soc.couples.wedding soc.culture.caribbean talk.philosophy.misc talk.politics.mideast
As you can see, there is a broad range to choose from.
At times Usenet with its plethora of newsgroups may appear complicated. New articles arrive, others may disappear before you get around to reading them, you subscribe to news groups, unsubscribe etc. Before starting to examine specific news readers and how these are used, we will first survey the functions you may expect to find in a news reader.
The article in newsgroups is quite similar to letters you get via electronic mail. The article consists of two parts. First there is a head, with administrative data about the article, including the author, subject, name of the newsgroup, date etc. In addition to this there is the text itself (the body).
Below is an example of an article in the newsgroup no.litteratur.
The head tells us the path taken from the news server the mail was originally entered on and the news server where I read the mail. We also see who wrote the mail, which newsgroups it was written to, as well as some other information which you can see in the head.
Each time you start your news reader, all new articles since your last visit to this newsgroup will have been added to the article list. Therefore you must check the news groups regularly.
Some news readers also have the added feature of automatically checking regularly whether there is any new article. This means that if you always have your news reader icon onscreen, it will alert you when new articles arrives.
Your news reader also tracks which article has been read and which has not been read. When you subscribe to a new group the news reader updates a file containing a record of read and unread article in the newsgroup in question. New articles are always tagged as unread until it has been read, or until you have explicitly commanded that these articles be considered as read.
Thus the news reader helps you keep track of which articles have been read, and which articles have not been read. This is very practical when there is a large amount of articles.
In time new articles spreads to all Usenet news servers. Each day brings new articles. Sooner or later the news servers' harddisks must reach saturation point. To avoid filling up harddisks a specific time limit has been set for newsgroup. How long articles will live is determined by the individual news server supervisor.
Several factors decide shelf life. If the news server disk space is at a premium, time limits for all articles will generally be short. Busy newsgroups with high activity and much articles always have short time limits. In newsgroups with heavy traffic including various binary files (images, video, sound etc.), the time limit is very short as these articles requires much storage space. A number of news servers actually do not subscribe to this type of newsgroup because they take too much disk space.
As the number of newsgroups is enormous the system is devised so that you must subscribe to those groups you are interested in. You then become a member of these selected groups, and every time you start your news reader it lists the newsgroups you subscribe to.
You may unsubscribe to a newsgroup at any time, as well as subscribe to another group whenever you feel the need. These operations are performed from within the news reader. When you close a session with your news reader, status information is stored about your group membership, as well as read and unread articles.
Writing and then posting articles to a newsgroup is as simple as writing and then sending e-mail. The difference is that you state a particular newsgroup as the receiver rather than a particular person.
In addition to composing your own article you may also reply to existing articles. The procedure corresponds closely to what you do when you reply to letters. When you have read the article, you select a command letting you write a reply to the article. You will then see the original text in an editing window. Delete most of the original text, but keep enough so that you can see what you are commenting on.
Discussions in newsgroups start with a main letter which other people comment on. This gets the ball rolling, and then there will be a constant stream of new articles, somebody commenting on the original articles, others commenting on the comments etc.
To help you follow all the articles in extended discussions of this type most news readers support threads. Threads are a method of linking all articles dealing with the same topic.
The figure below shows how the news reader News Xpress displays threads for the user by means of indents.
At the top of the figure you see the start of a thread about "Unauthorised felling of your neighbour's trees". First we see the main letter, then there are replies, and then an answer to a reply.
Most newsgroups permit anybody to write whatever they want. Because of this at times beginners could create some "noise". Somebody may stray on to grounds intended for serious discussions about subjects. The noise may manifest itself as unintended replies to articles, spaced or funny comments, and persons who "take over" the newsgroup and discuss totally different topics than the group was originally intended for. This is fully possible in open newsgroups.
To avoid this type of problem so-called moderated newsgroups may be established. Such groups appoint a moderator who scans all articles before posting it to the newsgroup. The mechanism functions so that all the articles to the newsgroup is automatically routed to the moderator who checks whether the article offers something new to the discussion before posting it to the news group.
Users might inadvertently send unfinished or empty articles, or even articles they wish they had not sent. This is unfortunate, as such articles will be taken as noise in the newsgroup. It is also quite unfortunate if you have written angry article which you later regret. The problem is that this article is distributed to all Usenet computers which subscribe to that newsgroup, and for very many of them that means all over the world.
Fortunately the news system offers a mechanism for the removal of such mail. Not all news readers have this feature, but News Xpress does.
The Internet has two different ways for you to take part in group discussions. One is news which we already have examined in the section "Electronic Conferences".
We shall now examine another way based on electronic mail where each participant is sent the discussion mail as e-mail directly to his/her own mailbox. This form of discussion is based on something called a mailing list, and the major difference from News is that the discussion may be restricted to a particular group of participants.
Mailing lists may be open or closed. Common to all of them is that only persons who are on the list will receive the letters or mail which are written to the mailing list. Closed mailing lists are created when a group of people who want to discuss a particular topic draw up a mailing list exclusively for themselves. The limit on membership ensures that this list is considered closed.
Such a mailing list may be established by the supervisor of a local list server, or this service may be purchased from an Internet provider, for example UNINETT.
Anybody may sign up for open mailing lists. There are thousands of this type of mailing list where different topics are under discussion. You will find more on signing up for such mailing lists below.
There are different systems for mailing lists. Two of them are LISTSERV and MAJORDOMO. These list-systems will be found on different servers all over the world. They have different commands and modes of operation. The following sections offer examples from a list server using the LISTSERV system.
For each mailing list there is a list manager whom you apply to when you subscribe and unsubscribe. The list manager may be a person, or it could be software which replies automatically and immediately. Remember that getting a subscription/unsubscription answer may take more time if the list is managed manually by a person.
Mailing lists work in the way that mail is sent to a particular
e-mail address. This mail is received by a so-called mailing list
server which functions as a message distributor.
Each discussion letter for the mailing list is first sent to this mailing list server. From there the mail is distributed to all the mailing list members directly to each member's mailbox.
The figure above shows an example of a mailing list called sales@business.no allowing the travelling sales personnel of this business to discuss different topics of common interest. Each of the members who have something to tell the other members all at once send mail to the e-mail address sales@business.no. This mail goes to the mailing list server and is distributed from there to all the members on the mailing list.
Regretfully there is no standard procedure for subscribing and unsubscribing. For some lists this occurs automatically, while for others a letter must be sent to the manager of the list. The commands used for automatic subscription/unsubscription are not standardised either, so this must be checked for each particular list.
Below are examples of how to subscribe to and take part in group discussions on open mailing lists of the LISTSERV type. This is only one example, there are many other mailing list servers.
You subscribe by mailing a letter to a particular address which you must know before you start. Names of lists can be found via colleagues, magazines, newsgroups etc. A well-known list server in Texas has the address
listserv@tamvm1.tamu.edu
By e-mailing a letter to the above address you obtain a listing of the mailing lists offered by this server. You may leave the subject field empty, and in the body you write the command list as shown in the figure below.
In a few minutes you will receive a listing of all mailing lists
offered by this list server. Below is an excerpt of the reply
when you send the command list
to the list server in Texas:
CSATEXAS Campus Safety list
DONTI Database of Networked Technical Information - Utilities/IDHCA
DONTI2 Database of Networked Technical Information - Utilities/IDHCA
DRUGHIED Drug Abatement Research Discussion
EHRDZENT Distance learning course e-mail forum
ENTOCAMP Entomology ReMail list - Total Development
ENTOEXT Remail List for Department of Entomology
FALBTI-L BTI/K200/NECU driver distribution list
FEEDLABL Texas State Chemist Feed Labeling discussion list
FINC632 Texas A&M University's Investment Mangement List
FOLKLORE Folklore Discussion List
FSPETAMU WKKF Food-Systems-Professions-Education-Initiative in Texas
GEOGLIFE Geography For Life: The Geography National Standards
GLOBALMC Global Marketing Consortium Discussion List
GRADDEVL Graduate Course Development Group
GUNDOG-L Gun Dog discussion list
HEDDVSTY Diversity issues facing Universities & Colleges
HUNTING Rec.hunting discussion list
IA-FAMS Information Associates' Financial Aid Software discussion
IATEX-L INFORMATION ASSOCIATES OF TEXAS USERS GROUP
IBMPC-L INFO-IBMPC Digest
Alias: INFO-IBMPC
INFO-LW LabWindows/CVI and LabWindows/Dos Technical Forum
INFO-VAX INFO-VAX Discussion
JOURALUM Texas A&M Former Journalsim Student Assn.
KIWANIS Interchapter Communications for Kiwanis International
LEADAAAE AAAE leadership working group
LEADRSHP A discussion list about all aspects of leadership
LINGUIST The LINGUIST Discussion List
MAES-L Society of Mexican American Engineers and Scientists
MAESTAMU Texas A&M Society of Mexican American
Engineers and Scientists
Pick one of the lists that might interest you and then subscribe to the list by e-mailing the same address as above with a command for subscription to a particular list. When subscribing to the list GRADDEVL Graduate Course Development Group as shown in the listing above, the following command is used
subscribe GRADDEVL Geir Maribu
So: first the command (subscribe), then the mailing list name, and finally your name. You do not have to give your e-mail address as the list server will retrieve that from the return address given in your letter.
Some minutes later there will be two return messages from the
list server. One of them is a confirmation of your subscription
as shown below.
[Graphics text here] Date: Tue, 1 Aug 1995 04:09:20 -0500 From: "L-Soft list server at Texas A&M (1.8b)" <LISTSERV@tamvm1.tamu.edu> Subject: Output of your job "geir" To: Geir Maribu <geir@IDB.HIST.NO> > subscribe GRADDEVL Geir Maribu You have been added to the GRADDEVL list.
The other message is general information about how the list works,
how to unsubscribe, and how to pick up more information. Message
no. 2 is shown in part below.
Date: Tue, 1 Aug 1995 04:09:19 -0500 From: "L-Soft list server at Texas A&M (1.8b)" <LISTSERV@tamvm1.tamu.edu> Subject: You are now subscribed to the GRADDEVL list To: Geir Maribu <geir@IDB.HIST.NO> Reply-To: GRADDEVL-Request@tamvm1.tamu.edu X-LSV-ListID: GRADDEVL Tue, 1 Aug 1995 04:09:19 Your subscription to the GRADDEVL list (Graduate Course Development Group) has been accepted. Please save this message for future reference, especially if you are not familiar with LISTSERV. This might look like a waste of disk space now, but in 6 months you will be glad you saved this information when you realize that you cannot remember what are the lists you are subscribed to, or what is the command to leave the list to avoid filling up your mailbox while you are on vacations. In fact, you should create a new mail folder for subscription confirmation messages like this one, and for the "welcome messages" from the list owners that you will occasionally receive after subscribing to a new list. To send a message to all the people currently subscribed to the list, just send mail to GRADDEVL@TAMVM1.TAMU.EDU. This is called "sending mail to the list", because you send mail to a single address and LISTSERV makes copies for all the people who have subscribed. This address (GRADDEVL@TAMVM1.TAMU.EDU) is also called the "list address". You must never try to send any command to that address, as it would be distributed to all the people who have subscribed. All commands must be sent to the "LISTSERV address", LISTSERV@TAMVM1.TAMU.EDU. It is very important to understand the difference between the two, but fortunately it is not complicated. The LISTSERV address is like a FAX number, and the list address is like a normal phone line. If you make your FAX call someone's regular phone number by mistake, it will be an unpleasant experience for him but you will probably be excused the first time. If you do it regularly, however, he will probably get upset and send you a nasty complaint. It is the same with mailing lists, with the difference that you are calling hundreds or thousands of people at the same time, so a lot more people get annoyed if you use the wrong number. You may leave the list at any time by sending a "SIGNOFF GRADDEVL" command to LISTSERV@TAMVM1.TAMU.EDU. You can also tell LISTSERV how you want it to confirm the receipt of messages you send to the list. If you do not trust the system, send a "SET GRADDEVL REPRO" command and LISTSERV will send you a copy of your own messages, so that you can see that the message was distributed and did not get damaged on the way .......
Remember to save this message in a folder so that you may retrieve the information on how to unsubscribe later.
After subscribing to a mailing list you must use the e-mail address of this list to communicate with the other members of the list. This address is always stated in one of the welcome messages. As a general rule the address where you send your messages is made up of the name of the list plus the domain name of the list server. In this case the mailing list is called GRADDEVL, so the e-mail address becomes
GRADDEVL@TAMVM1.TAMU.EDU
Letters sent to this list are automatically distributed to all
other members on the list.
It is important to realise the difference between using the two addresses above. LISTSERV@TAMVM1.TAMU.EDU is the e-mail address of the list manager and must only be used when signing on, signing off or when you need more information about how lists work etc. Letters/opinions are sent to the particular mailing list, and are distributed from there to all members on the list in question.
Avoid sending your unsubscription from a list to the list itself. It is a little pointless that all list members receive your message asking to be taken off the list. Your unsubscription must be sent to the list server, that is the address you used when signing on.
Remember to create a folder for each mailing list where you can store those messages you want to save. In this way you can store entire discussions which take place in mailing lists.
It is important to save the welcome message you received when
you subscribed to the mailing list as it tells you how to unsubscribe.
When you want to unsubscribe just check this message. In our example
e-mail is sent to the list manager which is
listserv@tamvm1.tamu.edu
and in addition you write the command
SIGNOFF GRADDEVL
in the message itself. In a few minutes you will receive confirmation
of your unsubscription, which will look like this:
From: "L-Soft list server at Texas A&M (1.8b)" <LISTSERV@tamvm1.tamu.edu> Subject: Output of your job "geir" To: Geir Maribu <geir@IDB.HIST.NO> > SIGNOFF GRADDEVL
You have now been removed from the GRADDEVL list.
File transfer means that files may be transferred between computers connected to the computer network. One computer may be your PC while the other computer may be any other computer on the Internet. You may download files to your PC or send files from your PC to another computer.
To transfer files you need a file transfer application and access to a user account and passwords for the computers to be transferred to/from.
A commonly used file transfer service is "anonymous FTP". Using this service you connect to a remote computer with the file transfer application FTP. On the remote computer a so-called "anonymous FTP" user account will already have been established and anyone can access this. Here you will be able to access a number of catalogues which contain files you may download.
This service is extensively used for the distribution of free software and for software upgrades.
Start your file transfer application by clicking on the FTP icon. The main application window comes onscreen, followed by the window shown below. Fill in the following text fields as shown in the figure. Profile name is your name on this FTP-server, that is a name you may choose freely. Host name is the full name of the FTP server, in this example ugle.unit.no. This is the FTP server of the University of Trondheim. Since this is an "anonymous FTP" you just check the Anonymous Login box. Click the Save button if you want to save this configuration for later use. Finally you click the OK button and you will be connected to the FTP server.
In this example the use of a password with the anonymous login
was quite simple. All you had to do was check the Anonymous
Login box. However, you should be aware that very often FTP
servers demand your e-mail address as the password, so that you
must state your password in the form
name@domain.no.
When connected, the main window looks like the figure below. On the left you see the directory tree and files on your local PC, on the right the corresponding information for the FTP server. Click your mouse pointer in the directory tree to navigate to the files you want. Normally you would know the name of the directory you want. When you have navigated to the right directory the listbox on the right will show the files.
Select one or more of the files in the listbox (select more than one by pressing the Shift key while clicking). Then click the arrow button pointing to the left to transfer the files from the FTP server to your PC.
If you did not change the directory on your PC, these files will go to the same directory where the FTP application resides. Normally you would not want to do this. Therefore you should remember to change to another directory by clicking the listbox on the left in the FTP window.
The file transfer itself may take a few minutes depending on the size of the file. A file of 100 Kbs will typically take approximately three minutes at a modem speed of 14,400 bps.
The Internet holds "tons" of information, and quite a large part of this has become directly useful. We want to make this information available to our students by setting assignments where the search for information on the net will be a natural part of their work.
There is an increasing number of search engines on the Internet which accumulate large indexed databases for all information available on the Internet. Using software on your local PC, these databases are available to you.
There is no doubt that you will find everything that is available on the net. Each word rendered on a Web page, for example, will be read by the search engines and placed in their huge database indexes.
These tools are simple to use. The real issue is making the technology available to the students. Everybody subscribing to the Internet via commercial Internet service providers will have these search engines at their disposal via World Wide Web.