Information Technology Reference
In-Depth Information
essentially one-way (server to browser) connections, to increasingly more
interactive exchanges. First came forms, where end-users could enter a small
amount of text into a field on the web page, or set a button or checkbox, and
have that information returned to the server for processing, or storage. In par-
allel, technologies were developed for the visual (WYSIWYG) editing of web
pages; and then for the synchronization of local copies of web documents with
the server copies. At this point these have been combined, so that the user can
be on a certain web site, and edit the appearance of the web page or create new
web pages. In this way the web server/client relationship has become very
interactive, and has allowed for the development of technologies such as
weblogs and wikis; and of social networking sites like Facebook, MySpace,
Flickr, YouTube and others. The impact on the nature of research and the
evolving roles of participant and researcher remains to be seen.
Currently, the protocols for web sites are fairly standardized: HTTP
(Hypertext Transport Protocol) for the transmission of data; HTML
(Hypertext Markup Language) and in some cases CSS (Cascading Style Sheets)
for the appearance of documents in a browser. HTML is most often written to
a document with a text editor or a visual web site creation tool, but in either
case it is stored as a static document on the web site. In some cases, for web
sites that are created in response to some event or feedback from a user, a pro-
gram is used to generate dynamically the HTML that is presented to the web
browser. The communication from a web form to the web server is based on
the CGI (Common Gateway Interface) standard. Information entered into text
fields, or checkboxes, is returned via the CGI to the program running on the
web server, which can then use the information to create a new web page.
These programs can be written in any programming language, but are very
often written in scripting languages such as perl, python, PHP and ruby. These
languages have strong built-in tools for parsing text (in the data processing
sense of separating continuous text into individual words or symbols of inter-
est) and recognizing patterns, which is one of the main tasks of a CGI program,
and additionally have tools for interacting with database software, which will
be seen to be useful.
Other computer-based communications methods, such as Usenet and Chat,
are increasingly being presented on top of a web-based interface as well. The
Usenet is one of the oldest internet communication technologies. The server
component is called a “news” server; it stores posted messages, and downloads
them to any subscribed user who checks for new messages. It is organized by
news groups, which have internet domain-like names, such as rec.food.cooking,
or soc.culture.thai, etc. The user interfaces to a Usenet server with a news
reader, which is often built into mail programs, as is the case for Outlook,
Thunderbird, and others. Users subscribe to individual Usenet groups, and the
news reader checks for any new messages in the group and downloads the
header and contents to the client. Users may post to the group by composing a
message and sending it. The technology and experience are very similar to an
