---------- Forwarded message ----------
Date: Tue, 20 Jun 1995 10:09:04 -0400
From: International Sociological Association <isa@sis.ucm.es>
To: chriscd@jhunix.hcf.jhu.edu
Subject: ISA Internet text
INTERNET: NETWORK "CULTURE" AND ITS
THREE "LEVELS"
INTRODUCTION AND "LEVEL ONE" - EMAIL
Although there are no strictly formal divisions, the
structure of the world-wide Internet computer network is
habitually divided into three "levels" of increasing complexity
but also of increasing facility for users (more "user friendly").
The "first level" is usually associated only with the simple
electronic mail (email) transmission and reception of messages
or files. This capacity has existed for several decades now,
although it has not been universally available to the public.
There have been many different email networks in the past but
almost all of them now belong the the Internet which has over
20 million users and is expanding daily.
The use of email is very straight forward and requires even
less familiarity with a computer than computer word processor
programs. After hocking-up to the Internet through a computer
(logging in), you usually type "mail", then the email address of
your correspondent followed by the text of the message you
want to send. To send an electronic file, you usually type
"mail", the email address of your correspondent and the name
of the file you want to send. Each email computer program (or
interface) has its own options which can often be quite
sophisticated and user friendly, but the content of this "first
level" of Internet "culture" remains essentially the email
transmission of messages and files. The following "second level"
involves more complex tasks such as sending the same message
or files to many correspondents on a pre-determined list.
"LEVEL TWO" - MAILING LISTS, FTP AND OTHER SERVICES
Mailing Lists are for the organized distribution by
computer networks of electronic messages and files. They can
involve either automatic management by a computer alone or
manual management (with at least some intervention by a
human moderator). In both cases, you usually send an email
message to the list's network address with the single word
"help" in the body of the message to receive in return an email
describing the list and how to subscribe to it.
Besides having a human moderator or not, mailing lists
have several other characteristics. They can be open (any email
message sent by anyone is automatically sent to all subscribers)
or closed (only subscribers can send email messages to the
other subscribers). Mailing lists can be public (open to anyone
who sends in an email message to subscribe) or private (your
request for subscription has to be accepted by the list's
moderator and can involve payment for membership in an
association or subscription to the list). The information
transmitted by a list to its members (subscribers) can be
automatic (any message by a member is sent to all list
members, thus resembling a Newsgroup - described below) or
moderated (all messages are sent to the moderator who then
decides whether or not to transmit them to all list members).
Names and email addresses of list members can be public
(available to anyone by email, often as with a Newsgroup),
private (available only to other list members) or closed
(available only to the moderator).
Finally, previous messages and files transmitted by the
list can be archived for further electronic access by list
members or simply deleted after transmission. To access such
stored information, one simply sends an email message saying
"get <file name>." Access to such stored information also leads
to another major type of email activity which is FTP (File
Transfer Protocol).
FILE TRANSFER PROTOCOL (FTP)
FTP (File Transfer Protocol) permits an email user to "get"
electronic files stored an another Internet-connected computer
and store them on the user's computer disk. The user can also
"put" locally stored computer files on another computer by FTP
when this is permitted by the receiving computer which is not
often the case. FTP constitutes one of the major advances in
communications and a major use of the Internet, if not the
major "irreplaceable" use of the Internet. Whereas email
messages can often be "replaced" by a telephone call or a fax,
there is no easy replacement for FTP other than the slow
alternative of mailing a copy of a file on a computer diskette.
To use FTP, you simply login on the Internet and type
"FTP". Then you type "open" plus the Internet address of the
FTP archives which interest you. The distant host server asks
your for a name and you can type "anonymous" or simply enter
a carriage-return. The host then asks for a "password" and you
enter your email address. You then have access to that host's
"anonymous FTP archives" and can copy whatever is permitted
by using the command "get" plus the name of the file. This
procedure is also at the origin of the name of "Anonymous FTP
Archives" usually employed by email users instead of simply
FTP.
The major disadvantage of FTP is that you only know what
is in a file by its succinct name. If that is not sufficient, you
either have to transfer the file and then read it, or else find
information on its contents from some other source.
Fortunately, these sources of information on file contents are
often available on the Internet in the form of Archie servers,
Gopher servers, Wide Area Information Servers (WAIS) and
World-Wide Web (WWW) servers. Archie servers, in particular,
are specifically intended for indexing information only on FTP
servers. But before moving on to this next level of the Internet
structure, let us look at other services associated with this
"second level" of the Internet.
OTHER "SECOND LEVEL" SERVICES
Here we find Newsgroups which are public electronic
forums and are for public discussion, debate and asking
questions. Although they are very entertaining and can
sometimes furnish surprising, specialized contributions, for
direct scientific work they are of secondary use and many
scientific "managers" consider them "a waste of time and
money."
There is also OPAC (Online Public Access Catalog) which
gives you access to over a thousand libraries whose card
catalogs are accessible on the Internet. This number increases
every week. Not only can you consult the card catalogs for
authors or titles, you can often search for books by topic as well
as have access to special documentation data bases.
A large number of serial publications are available on the
Internet. Most of these Electronic Serials are only published
electronically, but there are a growing number of electronic
versions of hardcopy (on paper) serials. Online serials cover an
astonishing variety of subject and can often furnish specialized
information and documentation.
Perhaps the most interesting among the remaining
"second level" services are the Archie servers which maintain
indexes that you can consult by email concerning the contents
of Anonymous FTP Archives. With Archie servers, you have
exhausted the "second level" of Internet structure and are ready
to move on to the "third" and highest level which included
Gopher, WAIS and WWW.
"LEVEL THREE" - GOPHER, WAIS AND WWW
Gopher servers go a step further than Archie servers. The
University of Minnesota's Micro-Computer and Workstation
Networks Center developed the Gopher protocol to provide
distributed document search and retrieval on the Internet.
When you ask your local Gopher server to search all other
Gopher servers (Archie and WAIS servers also) for the files you
want, it takes care of connecting to them all over the Internet
and then builds you a menu of the options returned by your
search. You then choose items from the menu and the local
Gopher server retrieves and stores the files for you.
WAIS (Wide Area Information Servers), developed by
Thinking Machines Corporation, is similar to Gopher. It
provides query services to data base indexes prepared
specifically for the WAIS system, as well as retrieval of located
items. WAIS servers vary substantially in their user programs
and their user friendliness, but the concept behind them is the
same. First you select the resources you want to search
through (Anonymous FTP Archives, Archie servers, some
Gopher servers, etc.), and then you provide a query containing
the information you want to search for. The local server sends
this information to the servers of the selected resources which
return any matches to the query. The local server then displays
a list of these matches, and you can select any of them for
retrieval and stocking locally.
WWW (World-Wide Web)is a system similar to WAIS and
Gopher but it has the advantage of also providing access to
these two other systems which do not necessarily provide
complete access to one another, nor to WWW. Therefore, WWW
is called a "hyper level" system since it is situated
hierarchically "above" both Gopher and WAIS.
The sharing of "cyberspace" (network resources such as a
Gopher or WWW server) can be considered to constitute a part
of this "third level" of electronic communication. At this level
"virtual" research groups (existing only on the Internet) or "co-
laboratories" are created. Despite their "virtual" nature, in
terms of communications and knowledge construction they are
indistinguishable from "real" physically located research
centers. This, along with the use of tele-conferencing, is the
highest level of electronic integration currently possible and is
only now getting underway.
This completes the panorama of Internet services at the
present time with its basic level of electronic transmission of
messages and files (email), its intermediary level of file
transmission, file indexing and online document services
(Mailing Lists, FTP, Newsgroups, OPAC, Archie), and its highest
level of integrated indexing, search and retrieval services
(Gopher, WAIS, WWW) and the possibility of sharing
"cyberspace" to create "virtual" research groups and "co-
laboratories."
In practical terms, most universities and research centers
have their own Internet address and resources, and sometime a
local server, ready for use by their members. The general public
can purchase these resources from local specialized
communications companies.
We would also like to thank the CCR (Centre Calcul
Recherche, Universite Pierre and Marie Curie - Paris VI, Tour
55-65, Etage 1, 4 place Jussieu, 75005 Paris) for its aid and
assistance not only in correcting this article, but also in
furnishing and maintaining a full range of Internet resources
which has permitted us to become familiar with the great
potential these tools represent for research communication.
Karl M. van Meter
bms@ext.jussieu.fr
(LASMAS-CNRS
59 rue Pouchet
75017 Paris;
tel/fax 33 1 40 51 85 19,
tel 33 1 40 25 10 01)