Title: The ELearning Lifecycle and its Services: The Web Services Approach
1The E-Learning Lifecycle and its Services The
Web Services Approach
- By Angad Grewal, Shri Rai,
- Rob Phillips and Chun Che Fung
2Overview
- The e-learning industry is moving forward. One
of the pressing issues at present is the strife
for common accepted standards so as to encourage
interoperability and reusability. - In our Interoperable E-Learning Infrastructure
Lifecycle using Web Services, all the e-Learning
components and learning objects would be well
established, effectively discovered and loosely
connected. - As we move towards a world of loosely coupled
applications capable of exchanging data freely
and communicating with a broad range of devices. - In a diverse environment where content,
delivery, management and analysis tools are being
produced by a number of vendors, interchanging
data and developing a common interface between
various components calls for development of
common standards.
3- Interoperability emphasizes the need to have a
standard communication methodology (protocols)
between various components of e-learning systems.
- Thus the use of open standards would allow
interoperability and reusability at different
stages of an e-learning solution. - One significant way of achieving
interoperability is through agreed standards and
specifications. These may be international or
local. There will be some local needs such as
curriculum requirements. The specifications and
standards may be generic such as HTML or they may
be for e-learning such as LOM.
4E-Learning Lifecycle
5ActorsThe list of actors who play an important
role in the lifecycle of a Digital Resource and
are listed below.
- 2.3.1 Actors
- The list of actors which were identified play an
important role in the lifecycle of a Digital
Resource and are listed below. - .
- a) The Creator uses a Creation Tool to create a
Digital Resource. An example of such a resource
is digital asset. - b) The Author uses an Authoring tool to put
existing content (such as text and graphics) into
a logical arrangement thus creating a Compound
Digital Asset of a Learning Object. Examples can
include Macromedia Flash, Macromedia Director,
Flash and Dreamweaver. - c) The Discoverer uses a Federated Search Engine
to discover existing digital content. Search
engine examples are Webfeat, Metalib and Fretwell
Downing. - d) The Librarian uses the Metadata Creation Tool
to describe the newly created digital resource. - e) The Organizer uses Sequencing tools to convert
simple learning objects into complex learning
objects. These complex learning objects can be
packaged as either IMS content packages or SCORM
Shareable Courseware Objects . These packages
contain a manifest, which describes the content
of the package. Such packages enable Learning
Management System to connect directly to a SCORM
manifest . - f) The Arranger uses a Learning Activity
Management System to structure digital resources
(e.g. complex learning object) into Learning
Activities . - g) The Learning Manager negotiates with the
Broker concerning the terms and conditions for
using the desired digital resource. - h) The Digital Rights Management can further be
divided into 3 actors - 1 The Intellectual Property (IP) Controller is
the one who creates IP Rights for a Digital
Resource. The IP rights for any given Digital
Resource is also checked. - 2 The Broker negotiates license deals (e.g.
permissions for modifying learning resources).
The Broker demands payment from the client or
customer. On receipt of such payments (e.g.
royalty payments), the broker allows access to
the customer. - 3 The Digital Rights Manager manages license
usage and tracks license usage.
6E-Learning lifecycle In detail
7Content Creation Authoring
By Dr Rob Phillips Murdoch University
8Components of E-learning Lifecycle
- Digital assets the electronic resource like a
image, chart, formula. - Content objects Digital assets contextualised,
e.g. adding text to tell the learner what to do
with the content like an image with supporting
text or labels - Learning objects consist of content object
directed towards a particular learning outcome,
with assessment to measure performance. - Below use case for each Digital Resource is
created by examining how each actor uses tools to
create/manage the Digital Resources.
9Digital Asset
- A Digital Asset is defined as any piece of
content that is created using technology. - It could be any remote electronic resource like
an image, chart, or even a formula. - A digital asset can be web-based or CD/DVD-based,
depending on file content and consumer needs.
10Compound Digital Asset
- Compound Digital Assets can be best described as
digital assets with contextualised information
(e.g. addition of metadata). - Examples for these are when some text is added to
a JPEG image or a description explaining a
mathematical formula.
11Arnold
The Context and the digital asset
ASSET
Contextualisation of the asset
tell the learner what to do with the
content
- Consider a picture of the Arnold, which is
readily available on the web. The definition
above says that this picture is not, in itself, a
learning object. - A range of learning objectives might be
facilitated by appropriately contextualizing this
particular image - We refer to the raw electronic source data of
the picture as a digital asset and to any
particular contextualization of it as a content
object.
Content Object
12Learning Object
- We have defined a Learning Object as the
aggregation of Digital Asset, Compound Digital
Asset and Metadata with a particular learning
purpose. - It is made up of two components - the object
content and its metadata - Example they can take the form of a
classroom-based electronic forum, or even a movie
clip (with some sort of educational value).
13Complex Learning Objects
- Complex Learning Objects are packages consisting
of structured assemblies of zero or more Digital
Assets, zero or more Compound Digital Assets and
one or more Learning Objects. - These packages can be in the form of well know
packaging formats like IMS or SCORM Shareable
Courseware Objects .
14SOA
- Advantages of SOA
- Existing services can more easily be reused
- Apps can expose their services in a standard way
- Applications can be exposed more easily to
diverse clientsWindows clients, ASP.NET/JSP, etc.
SOA
Application II
Application I
Common services
Application Platform Suite
- Application neutral services
- Maximize Reusability
- Self describing and self-contained
- Accessible from a variety of platforms
Java Virtual Machine
Operating System
Hardware
15What is a Web Service?
- A Web Service could be simply a service
available via the Web - This digital learning resource/service can be
implemented as Java application, C application,
Javascript code, etc. - Usually, web service means a resource that can
be accessed programmatically. - In this case they could be a services to Locate
and access remote learning object
16Web Services
- SOAP
- Simple Object Access Protocol
- XML message protocol for web services
- WSDL
- Web Services Description Language
- Allows programs to access descriptions of digital
learning services - UDDI
- Universal Description, Discovery and Integration
- Stores WSDL and other information about the web
services (which in this case could be a remote
Learning service)
17Web Services Standards
18This is how Web Services work with e-learning
Providers
1
Service Requestor
publish
Register Web Service(at development time)
UDDI Registry
WSDL Document
19Web Services and e-Learning Description Step wise
- When the learning services go live they are
registered in a service registry (UDDI), with a
description of the learning resource that
includes what it can do? and how to access it? - These descriptions are written in XML.
- The Service Requester (client) uses the
description and the other services in the
registry to determine how to invoke the service
and what response to expect in return. - Thus this description is specified in a standard
way by using WSDL. - WSDL document contains sections that describe
- What that particular service (Learning Resource)
can do? - The operations it can perform?
- The protocols used to access that service
(Learning Resource)? - Where and How to access the service?
- Once the desired service has been discovered and
its WSDL description used to determine its
capabilities, like where the service resides and
how to access it, the next step is to access or
invoke the service. - Thats where SOAP comes in, it is written in XML
- It defines a specification for how XLM massages
can be passed over a network. - Using SOAP as the standard protocol for
accessing learning resources (services) does not
tie the user to any particular transport method.
It can be used over HTTP,SMTP, FTP and etc.
20Search Services
Content Provider Y
Content Provider Z
Content Provider X
UDDI Registry
- Content Discovery Service
- Look up Service
- The Broker or Digital Rights Manager can discover
the desired learning content by sending a SOAP
Query to the UDDI Registry. - The information received from the UDDI Registry
is only partial, though the URI of the WSDL
document describing the Web Services is returned.
This will be the URI of the Web Service followed
by ?WSDL Examplehttp//myserver/service/learningc
ontent?WSDL - The Broker or Digital Rights Manager can get the
desired learning content by sending the a request
based on the URI retrieved from the UDDI
Registry. This is returned over a transport
protocol like HTTP.
Federated Search Engine A
Is Managed by the Broker or Digital rights
Manager
Federated Search Engine B
Learning Content Management System A
Learning Content Management System B
- Several services are registered in the UDDI
registry - These web services have been described as a WSDL
document the URI or which can be found while
accessing the UDDI - These services could be deployed at and remote
server - (ex Tomcat web server using the axis SOAP
engine) - Thus the LMS 1 and LMS 2 can use these services
to get access to remote learning objects.
Irrespective of the language they have been
written in. - With the help of these services LMS or LCMS
created by different vendors can re-use remote
learning objects
Content Discovery Service Stored and deployed in
a remote Web Server
Learning management System B
Learning management System A
Look up Service Stored and deployed in a remote
Web Server
21Sequence Diagram of the Creation Stage
22Sequence Diagram of the Authoring Stage
23Conclusion
- The objective behind using web services as a
middleware technology is to provide
interoperability in the e-learning framework,
right from the creation of a digital learning
objects to a fully packaged courseware being
delivered to a learner. - In this paper, we have tried to identify and
explain the steps involved in the creation of a
raw digital asset and how it is transformed into
a complex learning Object. This identification of
steps or stages has lead to the creation of
common services (which are also based on web
services). - These services (with real time web services
technology) would provide a common interface
between various components leading to platform
independence and interoperability between
learning systems.
24Thank you Any QUESTIONS Please?