Lesson 1 Web 2.0 – An Introduction

13 Pages·2008·0.23 MB·English

Lesson 1

Web 2.0 – An Introduction
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.1 Lesson Objectives

The concept of Web 2.0 is a new definition of the Web and the internet, that aims to
enhance creativity, information sharing and user collaboration. This lesson introduces
the key characteristics of Web 2.0. Important developments in web technology such as
the SaaS (Software as a service) model and multiple delivery channels are also
discussed in this lesson. The lesson also provides an explanation of internet based
folksonomies and social networking.

Building Rich Internet Applications with Adobe Flex 1-2
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.2 What is Web 2.0?

Web 2.0 is a term that describes the trend in the use of World Wide Web technology
and web design that aims to enhance creativity, information sharing, and, most notably,
collaboration among users. These concepts have led to the development and evolution
of web-based communities and hosted services, such as social-networking sites, wikis,
blogs, and folksonomies.

“Web 2.0 is the business revolution in the computer industry caused by the move
to the Internet as platform, and an attempt to understand the rules for success on that
new platform”.

Fig 1.2 Evolution of the Web

1.2.1 Types of Web 2.0 applications

Level-3 applications – These are the most "Web 2.0"-oriented applications and only
exist on the Internet. Level-3 applications derive their effectiveness from inter-human
connections and from the network effects that Web 2.0 makes possible. These
applications grow in effectiveness as people make more use of them. Examples include
eBay, Craigslist, Wikipedia, del.icio.us, Skype, dodgeball, and AdSense.
Level-2 applications - These can operate offline but gain advantages from going online.
An example of a Level-2 application is Flickr, which benefits from its shared photo-
database and from its community-generated tag database.
Level-1 applications – These can operate offline but gain features online. Examples
include Google Docs & Spreadsheets and iTunes music store.
Building Rich Internet Applications with Adobe Flex 1-3
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

Level-0 applications – These work both offline and online. The examples are MapQuest,
Yahoo! Local, and Google Maps (mapping-applications using contributions from users to
advantage could rank as "level 2").

Figure 1.2.1 Features of Web 2.0

1.2.2 Characteristics of Web 2.0

• Rich user experience
• User participation
• Dynamic content
• Metadata
• Web standards and scalability
• Openness
• Freedom
• Collective intelligence by way of user participation

Building Rich Internet Applications with Adobe Flex 1-4
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.3 Folksonomies and Web 2.0

Folksonomy is the practice and method of collaboratively creating and managing
tags to annotate and categorize content. Folksonomy is also known as collaborative
tagging, social classification, social indexing, and social tagging. In contrast to traditional
subject indexing, metadata is generated not only by experts but also by creators and
consumers of the content. Usually, freely chosen keywords are used instead of a
controlled vocabulary. The term Folksonomy is a blend of the words “folk” and
“taxonomy”. Hence, a folksonomy is a user-generated taxonomy.
Folksonomies became popular on the Web around 2004 with social software
applications such as social bookmarking or annotating photographs. Websites that
support tagging and the principle of folksonomy are referred to in the context of Web
2.0 because participation is very easy and tagging data is used in new ways to find
information. For example, tag clouds are frequently used to visualize the most used tags
of a folksonomy. The term folksonomy is also used to denote only the set of tags that
are created in social tagging.
Typically, folksonomies are Internet-based, although they are also used in other
contexts. Folksonomic tagging is intended to make a body of information increasingly
easy to search, discover, and navigate over time. A well-developed folksonomy is ideally
accessible as a shared vocabulary that is both originated by, and familiar to, its primary
users. Two widely cited examples of websites using folksonomic tagging are Flickr and
del.icio.us, although it has been suggested that Flickr is not a good example of
folksonomy.
As folksonomies develop in Internet-mediated social environments, users can
(generally) discover who created a given folksonomy tag, and see the other tags that
this person created. In this way, folksonomy users often discover the tag sets of another
user who tends to interpret and tag content in a way that makes sense to them. The
result is often an immediate and rewarding gain in the user's capacity to find related
content (a practice known as "pivot browsing”).
Folksonomy creation and searching tools are not part of the underlying World
Wide Web protocols. Folksonomies arise in Web-based communities where provisions
are made at the site level for creating and using tags. These communities are
established to enable Web users to label and share user-generated content, such as
photographs, or to collaboratively label existing content, such as Web sites, books,
works in the scientific and scholarly literatures, and blog entries.

Building Rich Internet Applications with Adobe Flex 1-5
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

Figure 1.3 Folksonomies

1.4 Software as a service
Software as a service (SaaS, typically pronounced 'Sass') is a model of software
deployment where an application is hosted as a service provided to customers across
the Internet.
SaaS eliminates the need to install and run the application on the customer's
own computer. As a result, SaaS eases the customer's burden of software maintenance,
operation, and support. Conversely, customers relinquish control over software versions
or changing requirements; moreover, costs to use the service become a continuous
expense, rather than a single expense at time of purchase. Using SaaS can also reduce
the expense of software purchases, through less costly, on-demand pricing. From the
software vendor's standpoint, SaaS has the attraction of providing stronger protection of
its intellectual property and establishing an ongoing revenue stream. The SaaS software
vendor may host the application on its own web server, or this function may be handled
by a third-party application service provider (ASP). This way, end users may reduce their
investment on server hardware too.

1.4.1 History
The concept of "software as a service" started to circulate prior to 1999 and was
considered to be "gaining acceptance in the marketplace" in Bennett et al., 1999 paper
on "Service Based Software".
Whilst the term "software as a service" was in common use, the CamelCase
acronym "SaaS" was not coined until several years later in a white paper called
"Strategic Backgrounder: Software as a Service" by the Software & Information
Industry's eBusiness Division published in Feb. 2001, but written in fall of 2000
according to internal Association records.
Building Rich Internet Applications with Adobe Flex 1-6
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.4.2 Philosophy of SaaS
As a term, SaaS is generally associated with business software and is typically
thought of as a low-cost way for businesses to obtain the same benefits of commercially
licensed, internally operated software without the associated complexity and high initial
cost. Consumer-oriented web-native software is generally known as Web 2.0 and not as
SaaS. Many types of software are well suited to the SaaS model, where customers may
have little interest or capability in software deployment, but do have substantial
computing needs. Application areas such as Customer relationship management (CRM),
video conferencing, human resources, IT service management, accounting, web
analytics, web content management and e-mail are some of the initial markets showing
SaaS success. The distinction between SaaS and earlier applications delivered over the
Internet is that SaaS solutions were developed specifically to leverage web technologies
such as the browser, thereby making them web-native. The data design and
architecture of SaaS applications are specifically built with a 'multi-tenant' backend, thus
enabling multiple customers or users to access a shared data model. This further
differentiates SaaS from client/server or 'ASP' (Application Service Provider) solutions in
that SaaS providers are leveraging enormous economies of scale in the deployment,
management, support and through the Software Development Lifecycle.

1.4.3 Key characteristics of
software delivered by SaaS

The key characteristics of SaaS software, according to IDC, include:
• Network-based access to, and management of, commercially available software
activities that are managed from central locations rather than at each customer's
Site.
• Enabling customers to access applications remotely via the Web application
delivery that typically is closer to a one-to-many model (single instance, multi-
tenant architecture) than to a one-to-one model, including architecture, pricing,
partnering, and management characteristics.
• Centralized feature updating, which eliminates the need for downloadable
patches and upgrades.
• SaaS applications are generally priced on a per-user basis, sometimes with a
relatively small minimum number of users and often with additional fees for extra
bandwidth and storage. SaaS revenue streams to the vendor are therefore lower
initially than traditional software license fees, but are also recurring, and
therefore viewed as more predictable, much like maintenance fees for licensed
software.
Building Rich Internet Applications with Adobe Flex 1-7
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.4.4 SaaS Implementation
According to Microsoft, SaaS architectures generally can be classified as belonging to
one of four "maturity levels," whose key attributes are configurability, multi-tenant
efficiency, and scalability. Each level is distinguished from the previous one by the
addition of one of those three attributes:
Level 1 - Ad-Hoc/Custom: At the first level of maturity, each customer has its own
customized version of the hosted application and runs its own instance of the application
on the host's servers. Migrating a traditional non-networked or client-server application
to this level of SaaS typically requires the least development effort and reduces
operating costs by consolidating server hardware and administration.
Level 2 - Configurable: The second maturity level provides greater program flexibility
through configurable metadata, so that many customers can use separate instances of
the same application code. This allows the vendor to meet the different needs of each
customer through detailed configuration options, while simplifying maintenance and
updating of a common code base.
Level 3 - Configurable, Multi-Tenant-Efficient: The third maturity level adds multi-
tenancy to the second level, so that a single program instance serves all customers. This
approach enables more efficient use of server resources without any apparent difference
to the end user, but ultimately is limited in its scalability.
Level 4 - Scalable, Configurable, Multi-Tenant-Efficient: At the fourth and final SaaS
maturity level, scalability is added through a multitier architecture supporting a load-
balanced farm of identical application instances, running on a variable number of
servers. The system's capacity can be increased or decreased to match demand by
adding or removing servers, without the need for any further alteration of application
software architecture.
Virtualization also may be used in SaaS architectures, either in addition to multi-
tenancy, or in place of it. One of the principal benefits of virtualization is that it can
increase the system's capacity without additional programming. On the other hand, a
considerable amount of programming may be required to construct a more efficient,
multi-tenant application. Combining multi-tenancy and virtualization provides still greater
flexibility to tune the system for optimal performance. In addition to full operating
system-level virtualization, other virtualization techniques applied to SaaS include
application virtualization and virtual appliances.
Various types of software components and frameworks may be employed in the
development of SaaS applications. These tools can reduce the time to market and cost
of converting a traditional on-premise software product or building and deploying a new
SaaS solution. Examples include components for subscription management, grid
computing software, web application frameworks, and complete SaaS platform products.

Building Rich Internet Applications with Adobe Flex 1-8
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

1.5 Multiple Delivery Channels (Voice-
VOXML and ANT(HTML))

1.5.1 What is VoiceXML?

VoiceXML is a Web-based markup language for representing human computer
dialogs using audio output devices (computer-synthesized and/or recorded) and audio
input device (voice and/or keypad tones).

1.5.2 Architectural Model

Figure 1.5.2 VoiceXML Architectural Model

Document Server: process request form a client,ex. a web server.
VoiceXML Interpreter: process VoiceXML documents and conduct the dialog.
VoiceXML Interpreter Context: acquire VoiceXML documents, detect and answer
calls.
Building Rich Internet Applications with Adobe Flex 1-9
______________________________________________________________________________
Lesson 1: Web 2.0 – An Introduction
_____________________________________________________________________________

Implementation Platform: controlled by VoiceXML Interpreter Context and VoiceXML
Interpreter;generate events in response to user actions and system
events;require: audio output(TTS, audio files),audio input (SR,audio record, DTMF).

1.5.3 Voice applications

• Information retrieval
• Electronic transactions
• Telephone services – Call centers
• Voice e-mail
• Voice Access Control – Voice Recognition

1.5.4 VoiceXML History

Figure 1.5.4 VoiceXML History

1.5.5 Usage

Many commercial VoiceXML applications have been deployed, processing millions
of telephone calls per day. These applications include: order inquiry, package tracking,
driving directions, emergency notification, wake-up, flight tracking, voice access to
email, customer relationship management, prescription refilling, audio newsmagazines,
voice dialing, real-estate information and national directory assistance applications.
Building Rich Internet Applications with Adobe Flex 1-10
______________________________________________________________________________