10-05-2013, 04:27 PM
Towards an Accessible Web by Applying PUSH Technology
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Abstract
Information overload makes it more and more difficult to get the right information at the
right time. Nowadays, users get overwhelmed by the massive amount of information available on the
Internet. The 'traditional' pull technology model is becoming a limit for more efficient use of the Web.
Specifically requesting information from a particular source, e.g. downloading a Web page with a
browser is an example of pull technology. As Web grows in size and complexity the importance of new
information delivery models such as push technology increases. The push technology was created to
alleviate problems facing users of the Internet, e.g. information overload and low bandwidth. The push
technology is a data distribution technology in which selected data is automatically delivered into the
user's computer at prescribed intervals or based on some event that occurs. The push technology can be
used to make information more accessible for the user. By applying the push technology it is possible
to design and implement user-friendly and effective information delivery systems. In this paper we first
define what the push technology is. We will also describe what the advantages and disadvantages of the
push technology are, and how we can utilise it best. This paper also contains a table where basic
information about 50 different push tools has been collected.
INTRODUCTION
Internet and Web (World Wide Web) serve acquisition and distribution of information very
widely at the moment. The 'traditional' pull technology model is becoming a limit for more
efficient use of the Web. In the pull technology model the user specifically asks for
something by performing a search or requesting an existing report, video or other data type.
This has to be repeated for each Web site from which the user wants to get useful
information. Often these searches result in hundreds of thousands of items returned. To get
fast the updated information is not easy. With an increasing number of Web sites, combined
with the quite slow transfer rate for dial-up users, the task results in a lot of wasted time and a
higher telephone bill. As Web grows in size and complexity the importance of new
information delivery models such as push technology increases. The push technology is a
data distribution technology in which selected (customised/personalised) data is
automatically delivered into the user's computer at prescribed intervals or based on some
event that occurs. The difference between push and pull technologies centers upon the side
which is initiating the transaction. The transaction is either initiated on the user/client side
(pull) or on the provider/server side (push).
WHAT IS PUSH?
The push technology has rapidly gained considerable popularity since its emergence in April
1996, the time PointCast announced its PointCast Network, which soon became extremely
popular. It pushes selected news and stock quotes into a user's machine at prescribed
intervals. Since then, a number of similar solutions have been proposed and deployed on the
Internet. Push is also know as "webcasting", "netcasting" or "PointCasting" (after the
company that invented it). When applied appropriately, it can be used to solve real business
problems.
The push technology was created to alleviate problems facing users of the Internet, e.g.
information overload and low bandwidth. Information overload is the main driver for the
development of push services. It is a natural evolution required to cope with the amount of
information now available over the Internet. The push technology can be augmented by
filtering, indexing, and directory services to help manage information overload. Most end
users are restricted to low bandwidth Internet connections making it difficult to receive e.g.
multimedia content. Assuming users are willing to wait 15 seconds for a Web page to
download. This leaves room for little more than text and small graphics. The push technology
provides the means to pre-deliver much larger packages of content (with an unattended
connection). This leaves plenty of room for multimedia content such as audio, large graphics,
or short video clips.
PUSH AND USER INTERFACE ASPECTS
Push users can access their information in a variety of ways and they are not limited to how,
why or when they get the information they need. Simplicity of use is the key factor for push
services. Personalised services are a key to simplifying user interfaces. The push technology
allows user profiles to be used to set up personalised information delivery systems.
The information coming to a user's workstation is usually a summary of a larger document
that the user can access by requesting additional details. By clicking on a headline the full
article appears on the screen. Some of that information, such as news headlines, could be
presented in the form of a screen saver (the animations that scroll across a monitor when a
computer is temporarily inactive). Personalised screen savers keep the user informed of the
latest news with headlines that scroll across the screen. Other data, such as sports scores and
stock prices, might be placed in a ticker. A ticker is a movable, resizable, bar-shaped window
that appears on the screen, that scrolls time sensitive information from channels the user has
subscribed to. The ticker can even display news while the user works in other applications. A
ticker bar embeds and scrolls in the title bar of any active application. It can even
automatically follow the user from one active application to the next. The most common type
of display in BackWeb is the flash. Flashes are interactive multimedia displays that
proactively alert users to the arrival of content without interfering with their active
application. Clicking on an flash launches the Web browser with the complete article intact.
PUSH APPLICATIONS
The push technology is useful in many different types of applications. The push technology
has been used for a number of years in the financial world, in live news feeds and cable
television. One of the more common uses today is the automatic downloading of software
upgrades and fixes and the delivery of news information to workstations. Push is useful to the
end user because it prequalifies appropriate information, thus cutting down on research time.
It is also vital to the companies or services that use push to sell their products and services.
Push Application Case
We have been designing and implementing a push application for the EIONET (European
Environment Information and Observation Network) to intensify the acquisition and
distribution of the environmental information of the European Environment Agency (EEA).
EIONET is a co-operative organizational network of institutions that assists the European
Environment Agency in providing the European Community and its member states with
environmental information. It also allows electronic interchange of information between
these organisations. EIONET is currently an intranet connecting multiple national hosts
(intranet nodes). The purpose of the project was to provide a push application for delivering
notifications on new documents and events published on a Web repository.
PUSH MARKET
The push market can be divided into four basic categories [3]:
x Application distributor. These products enable you to automatically deliver simple
applications to your end users. E.g. products like Marimba's Castanet.
x Content aggregator. These products gather content, format it in a consistent wrapper, and
push it to your workstation before you even ask for it. E.g. products like PointCast
Business Network.
CONCLUSIONS
We have been designing and implementing a push application and also have obtained basic
information about 50 push products. We have tested several products. By applying push
technology we can design and implement user-friendly and effective information delivery
systems. These systems can be general enough so that they can be applied to other
environments with reasonable amount of work. As Web grows in size and complexity the
importance of new information delivery models such as the push technology increases.
Dramatic increase of data traffic on the Internet has made information access periodically
difficult to achieve. The push technology can be used to make information more accessible
for the user.