Visits to EdNA Online since November 2000 have risen from more than 50,000 to more than 200,000 per month.
Garry Putland, Director EdNA Online, 178 Fullarton Rd, Dulwich SA 5065. gputland@educationau.edu.au,
Jerry Leeson, Project Manager EdNA Online, 178 Fullarton Rd, Dulwich SA 5065. jleeson@educationau.edu.au
Geoff Hendrick, Technical Architect EdNA Online, 178 Fullarton Rd, Dulwich SA 5065. ghendrick@educationau.edu.au
Jenny Millea and Nelly Ivanova are acknowledged as contributors to this paper.
EdNA (Education Network Australia) is a highly regarded national collaborative model of networking for the Australian education and training community, and EdNA Online is the virtual network of learning environments and a gateway to educational and training resources and services. This online service, built on the principles of collaboration and distributed contribution and management of resources, is the vehicle and mechanism through which the EdNA national collaborative model operates.
Today, EdNA Online is a trusted, well-resourced information and knowledge base for educators and learners alike. Organised around Australian curriculum and competencies, it is gateway to freely available, web-based teaching and learning materials and communication tools, and is at the forefront of implementing the latest Internet standards such as XML for web services.
The unique role of EdNA Online in today's education and training information space was identified in a recent report as '(...) the only site that (...) has all the following features:
The creation of Education Network Australia (EdNA) was a response to changes
in education and training made possible in the 1990s by improved information
and communications technologies (ICTs). The concept a national network of cooperation
and collaboration between all education and training sectors in Australia coincided
with the release of some important documents and reports. Some significant publications
include the 'Creative Nation' statement, announced in 1994 by the then Prime
Minister, Paul Keating, and 'The Networked Nation', published in 1994 by the
Australian Science and Technology Council.
Alongside Commonwealth Government initiatives, state-based education and training
systems also made efforts to capture new opportunities. Education and training
authorities provided funding for Internet connectivity, teachers were offered
professional development opportunities, and projects on exchanging and sharing
of teaching and learning resources online were planned.
By the mid 1990s the Commonwealth and State/Territory education departments became aware that these individual initiatives and projects could be streamlined through a national collaborative network, within which stakeholders would share knowledge of common issues while pursuing solutions, avoiding duplication in effort, and thus minimising costs.
The foundations of the physical network, EdNA, were established 1995 by a number
of national working and reference groups - the EdNA Network Business Requirements
Reference Group, followed by the EdNA Reference Committee (now Australian Information
and Communications Technology in Education Committee - AICTEC) with representatives
from each education and training sector. The EdNA Task Force, established by
the then Department of Education, Employment, Training and Youth Affairs (DEETYA),
was responsible for managing the initiative.
The EdNA network consists of multiple layers of 'networks', both technical and
professional, which interlink where appropriate. The formal social network created
by and through EdNA has also promulgated informal communities of interest. The
sharing of initiatives, leading practice, innovation, and research has lead
to communities of interest where new knowledge is developed collaboratively.
EdNA Online was the first database-driven educational website in Australia, built around the concept of a browsable and searchable directory of online resources. Some of the key components of the first generation EdNA system were an Oracle database, a combination of the Verity search engine with a Harvest freeware robot; Majordomo mailing lists set up to accommodate the networking needs of the EdNA stakeholders; and a Noticeboard system based on the Network News Transport Protocol (NNTP). The resources collection was built using a manual and automated process simultaneously, whereby web accessible resources were evaluated according to selection criteria, and from this core pool linked documents were automatically harvested and indexed separately - the automated harvesting process was one of the first in Australia.
Resources were described using Dublin Core metadata and the EdNA Online database was a repository for these metadata records about education and training resources. In time, EdNA Online developed its own set of metadata elements - the EdNA Metadata Standard [HREF2]. The Standard was developed in consultation with all sectors of education and training, with the goal of the EdNA Metadata Standard from an organisational point of view was firstly, to provide a consistent, flexible and extensible structure for the description of online resources related to education and training, and secondly, to provide a platform for interoperability with the state and territory education systems [HREF3]. A distributed model of administration was enabled through a system of security groups, to allow maintenance of the database and other functions by information officers, appointed by each of the education and training sectors.
Today, EdNA Online is underpinned by three parallel business models based upon a Service Oriented Architecture (SOA) and related to information service delivery.
The first generation EdNA Online was conceived of using the 'retail model'
- EdNA Online a one-stop-shop for education and training resources where users
came to the site to access the information. This EdNA Online retail interface
at http://www.edna.edu.au/ continues to attract large numbers of visitors.
Visits to EdNA Online since November 2000 have risen from more than 50,000 to
more than 200,000 per month.
Page Views for EdNA Online in the same period have increased from half a million per month to around 1.5 million per month.
Between 2000 and 2003 developments in information and communication technologies have provided significant opportunities to leverage, share and expand the EdNA Online services by embedding them into other education and training websites and portals. EdNA Online is moving towards a new model aiming to position itself as an aggregator of national and international quality evaluated online resources and distributed online services.
When considering the intermediary/aggregator business model, it is important restate that EdNA Online is a metadata repository that holds metadata records about online resources related to education and training. This enables EdNA Online to provide information about a resource without the need to maintain the resource itself. The EdNA metadata, and implementation of multiple controlled vocabularies, assist in resource discovery and creation of dynamic categorisation of resources.
EdNA Online has the capacity to export all or some of its metadata to other repositories. It also has the capacity to harvest [or import] records from other metadata repositories. The distributed administration system for the harvesting process enables authorised stakeholders to manage the process and the records themselves. As an intermediary/aggregator, EdNA Online forms formal relationships with other organisations and repositories through Memorandums of Understanding (MoUs) and Contributing Stakeholder Agreements (CSAs) which establish business rules, expectations, and mutual responsibility for the parties involved. These agreements usually involve a workplan for activities. For example, EdNA Online has MoUs and workplans agreed with MERLOT, a US repository of higher education resources, European SchoolsNet, and TKI - the New Zealand schools repository.
At a national level, the sharing and exchange of metadata records provides a high return on investment for stakeholders and organisations that publish quality resources for education and training sector, or records about those resources.
The wholesale business model positions EdNA Online amongst the most innovative providers of web services using emerging technologies such as XML and RSS. Web services are the glue that will link together web deployed components to form web applications [HREF4]
One way of delivering web services is through the exchange or sharing of metadata
records, held by EdNA Online as an aggregator, with education and training portals
and websites using XML APIs. A good example of this wholesale model in operation
is the Government Education Portal (http://www.education.gov.au).
It demonstrates the repurposing of the EdNA Online repository to provide a customised
browsable view of metadata records relevant to a particular audience. In this
case, the site provides access to Commonwealth and State government information
about education and training in Australia as part of the Commonwealth Government's
Customer-Focussed Portals Strategy. The Government Education Portal also uses
the EdNA Online search function. The use of an XML Search enables a call from
the Government Education Portal to interrogate EdNA Online and return relevant
resources.
Workplans with alliance partners also involve the development and provision
of distributed searches - for example the EdNA Search API can include distributed
parallel searching of other repositories. An example of this is an outcome of
the Memorandum of Understanding signed with MERLOT, where the workplan involves
collaboration in the development of distributed searching. MERLOT is now able
to search the EdNA Online repository and EdNA Online has the capacity to search
the MERLOT repository.
In early 2003 the IMS Global Learning Consortium released a final (version 1.0) specification on Digital Repositories Interoperability, consisting of three parts: an Information Model, a Best Practices Guide, and an XML Binding. This specification provides a good foundation from which to conceive and deploy integrated search services across heterogeneous and distributed repositories. This model is the basis for the EdNA Online distributed searching model.
In the Information Model a range of use cases is outlined:
Notes: This is adapted from IMS DRI Information Model. DRI is Digital Repositories Interoperability. LCMS is Learning Content Management Systems.
EdNA Online has developed a suite of applications, which implement this reference model. These include a range of XML services including noticeboards, RSS feeds of news headlines and newsletters, as well as the search and browse XML APIs.
The three business models running in parallel provide the Australian education and training sector with access to a variety of quality assured information that can be accessed and delivered to their web portals and websites and leverage EdNA Online's role as an interoperable aggregator of resources, and its intermediary role as distributor.
This section of the paper lays out EdNA Online's technical infrastructure. Today's business operating environment requires that IT organisations identify and plan for an architecture that can not only provide for scalability but also 'agility' - the ability to add new offering or reorient existing functions in a highly flexible manner. The agility requires that we think of IT in terms of services, not physical assets. [HREF5]
In the first generation of EdNA Online, the system architecture and design, software development and maintenance and site hosting and operations were all outsourced.
The technical infrastructure was comprised of the following:
Links to externally hosted forum tools (Janison Toolbox).
Rapid changes in information and communications technologies, as well as in the education and training sector, made it clear that the technical architecture and management of EdNA Online needed to be re-thought to provide a technical environment that was more agile and flexible and could respond rapidly to change and to meeting stakeholders' needs.
Major drivers for this shift were:
In order to better align with this dynamic and rapidly changing business and technical environment the EdNA Online technical architecture is being re-engineered in a modular, standards-based services-oriented model with the following major components:
The new EdNA Online architecture is depicted in the diagrams on the following pages:
The following diagram describes the overall high-level Services Architecture and shows how it supports the three business models via three service interfaces:
The following diagram describes the relationship between the resource discovery service and the Aggregation Service. The EdNA Online metadata repository contains two types of collections:
When a service user (a person or a web portal accessing the EdNA Online search web service) makes a search request the EdNA distributed search engine initiates multiple concurrent search requests to:
The search results are then combined and presented to the user.
The distributed Search Architecture is shown in more detail below. The distributed search engine contains a number of search adaptors which are capable of searching external sites via the most common search protocols:
The Communications/Content Syndication Architecture is shown below. EdNA Online content (news headlines, newsletters, summaries of items that have been recently added to the metadata repository) can be syndicated in HTML and RSS format using both push and pull models.
The following diagram shows a scenario whereby an education institution builds a local portal that embeds the EdNA Online distributed search service. In this scenario the institution web portal's search interface offers the end user a "Search locally" and a "Search EdNA Online" option. When the user enters some keywords and selects the "Search EdNA Online" option the request is sent to EdNA Online as a HTTP/XML request. EdNA Online conducts the search (via concurrent searching of the local repository and multiple external repositories) and returns the result set to the institution web portal as an XML structure. The institution web portal formats this XML using its own HTML look and feel and presents the results to its end user.
The architecture of the new EdNA Online Portal is shown below. The Portal provides:
The following diagram shows how the EdNA Online front end portal consumes the EdNA Online back end web services to deliver its functionality to end users. The diagram also shows how any other portal can access the same services. The EdNA Online back-end server provides functionality such as:
The front end portal (via portlets) accesses these services via the XML API and renders them onto the end user's customised web pages.
The new EdNA Online architecture is based on a platform of adherence to key industry standards as described in the table below.
|
Standard
|
Name of Standard
|
| For Internet Transport | HTTPv1.1 |
| For Internet File Transfer | FTP (RFC 959) with restart and recovery HTTP (RFC 2626) for file transfer |
| For Email | SMTP/MIME (multiple RFCs) |
| For Resource Discovery | Dublin Core DCMI metadata V1.1, DC Qualifiers EdNA Metadata Standard V1.1RDF |
| For Vocabulary | AGIFTSCIS, ScOT, ATED, VOCED, OZJAC |
| For Metadata Definition of content | W3C XML schema |
| For Data transformation | XSL (Extensible Stylesheet Language) http://www.w3.org/TR/xsl/ |
| For Data modeling and description | UML (Unified Modelling Language http://ww.omg.org/gettingstarted/ RDF (Resource Discovery Framework) http://www.w3.org/TR/REC-rdf-syntaxspecsandprods.htm |
| For Web services description | Web Services Description Language (WSDL) http://www.w3c.org/TR/wsdl/ |
| For Web Services Transport | Simple Object Access Protocol (SOAP) http://www.w3.org/TR/SOAP/ |
| For Web services directory | Universal Description, Discover and Integration (UDDI) http://www.uddi.org/ |
| For Metadata Repository Interchange | OAI, IMS DRI, RDF |
| For Distributed Searching | Z39.50, ZING (SRW/SRU), Google SOAP XML API |
| Content Syndication | RSS 0.9, RSS 1.0 |
| Software Development | Java |
| Application Framework | J2EE |
| Java Portlets | API JSR 168 |
| Web Presentation and Accessibility | W3C Accessibility Priority 3, HTML 4, CSS, GIF, XHTML, XML/XSLT |
Internationally, open source technologies have gained legitimacy with some governments and education organisations looking to capitalise on the work already done using open source, and to contribute back into the open source community for mutual benefit.
As an organisation with collaboration at its core the open source model is appealing one for EdNA Online. Further, open source now has the capacity to provide enterprise level systems which are robust and reliable, and replace expensive commercial products. For education and training organisations and sectors, keeping ongoing costs to a minimum while maximising the sophistication and breadth of service delivery is a major driver.
The table below describes open source replacement implementations that we have
either completed or are actively evaluating.
|
Component
|
Legacy Product
|
Open Source Replacement
|
| Operating System | Solaris | Linux |
| Hardware Platform | Single Sun Enterprise class server | Cluster of low cost Intel Linux servers |
| Web Server | Netscape | Apache |
| Web Application Server | Tomcat | |
| Portal/Content Management System | Custom-built, HarvestRoad | DPMS Jetspeed/Jahia |
| Database | Oracle | Postgres |
| Search Engine | Verity | Lucene |
| Mail List Server | Lyris | Mailman |
| Collaborative Workspace | Mimerdesk, Jive Forums, Roller | |
| Single Sign on | Liberty |
EdNA Online is the culmination of collaboration between its stakeholders. Collaboration is a fundamental aspect of the development methodology used in the transformation of the EdNA Online website to a suite of online services. Part of that collaboration involves prototyping the functionality being built and using an iterative development model. In order to prototype successfully, EdNA Online deployed technologies that modelled the functionality sought, quickly and at a low cost. Product evaluation included a number of proprietary applications, as well as open source applications. By deploying open source software, EdNA Online is able to engage its stakeholders in the requirements gathering process and use the open source tools to facilitate the process without having to resort to purchasing expensive software licenses. A number of open source software tools have been used to facilitate this process.
In order to deploy EdNA Online services into other portals successfully, it is necessary to use widely accepted standards. It is also important that the services can be easily implemented in other portals. Experience has shown that newsfeed services are easily implemented and widely accepted using an XML format called RSS [HREF7]. There are many RSS newsreader and content creation programs freely available on the web. EdNA Online currently supports RSS 0.9 and 1.0 for the delivery of newsfeeds.
The most complex function that EdNA Online offers as an online service is the metadata repository search. EdNA Online stakeholders have, or have access to, varying levels of technical ability for their websites. To accommodate different levels of technical ability, the EdNA Online search and browse functions are available in different formats. For owners of websites that do not have access to web developers, HTML scripts that can be downloaded from the EdNA Online site and pasted as HTML into their websites are provided. This provides all the EdNA Online search functionality, and presents results in a default format. For more advanced website owners XML-based services are provided. HTTP APIs for EdNA web services are available. The search and browse results are returned as XML strings that the website owners can then present onto their sites with their own look and feel.
The Intermediary/Aggregation model allows EdNA Online to act as a conduit to a number of quality, evaluated repositories. The distributed search function allows users to search multiple repositories within a single search and be assured that the results returned are quality resources. Providing this functionality is an immense benefit to EdNA Online users; however delivering the capability creates a number of interesting challenges. Users of EdNA Online are accustomed to the delivery of search results within a well-known timeframe. Additionally, general web search engines deliver results very quickly, even if the quality of those results does not always meet user expectations.
Distributed searching, however, is complex and the performance overhead increases
dramatically as the number of repositories being searched increases. As a consequence
different ways of delivering search results to users are being investigated.
For example, repositories do not all return results within the same timeframe.
The simplest strategy is to wait until all repositories have returned (some)
results and then to display the combined results. However, users may not want
to wait this long and would prefer results to be displayed as they are returned.
This has implications for the order in which results are displayed. Using the
latter strategy, it is not possible to order all the results by their ranking.
And different repositories also use different ranking techniques, which creates
a challenge for ranking combined results meaningfully.
Adding to that complexity is that search engines change their interfaces from time-to-time. This means that the EdNA Online web service interface for the XML search API needs to be changed.
By searching these repositories through a single interface, EdNA Online is able to remove this burden from its stakeholders.
EdNA Online services are now available through multiple access points. Casual visitors can continue to visit the EdNA Online retail website. They will benefit from some of the new functionality - such as the distributed search of multiple repositories. Visitors who choose to register with the new EdNA Online will have access to all the functionality of the casual visitors plus access to the collaborative tools and personalisation functions. The number of services and amount of information in EdNA Online is substantial and a criticism in the past has been that by having to cater to such a diverse user population, it has been difficult for a user to navigate to information of particular relevance to them.
When a visitor registers with EdNA Online, they provide their education sector as part of their profile. The default content presented to them is customised to display information relevant to their sector. For example, a higher education user will see newsfeeds relevant to the higher education sector. From there, the visitor can then personalise the information that they see on their own 'home page'.
Continuing the example of the higher education visitor, that person might decide that instead of seeing newsfeeds for the higher education sector, they would like the school sector newsfeeds as that might be relevant to their work. Instead of seeing the Recent Items newsfeed for Higher Education, they may choose to see all Recent Items. The amount of information they see and the number of feeds, as well as the manner in which they are presented are also customisable, as are their default search parameters. In fact, each of the web services is customisable by the visitor.
There are stakeholders that have their own web presence and wish to access EdNA Online services through their own sites. All EdNA Online web services can be delivered to these sites. An example here could be a TAFE institution that has its own portal. It may interested in the EdNA Online newsfeeds for the VET sector and would also like access to the distributed search functionality.
These are distributed as web services that are easily implemented within the TAFE's portal infrastructure and the presentation of the information can be tailored to meet the look and feel of that portal.
Another example is a school with its own Intranet. A teacher manages the Intranet in his/her own time and has limited web experience. The teacher uses the EdNA Online Search regularly and would like to access it from the Intranet. Rather than deploy the XML-based web service the teacher downloads the HTML for the EdNA Online search and pastes that into a web-page on the Intranet. The EdNA Online search is now available on that Intranet.
The EdNA Online System Architecture has been re-engineered to align more closely with the newly articulated business models for EdNA Online service delivery.
The Services-oriented architecture supports parallel and modular development of:
The EdNA Online back-end web services can be embedded in stakeholder web portals to enable integration and delivery of EdNA Online functionality with stakeholder functionality to local users with local site look and feel.
The EdNA aggregation services enable EdNA Online to provide a 'deep web' metadata-driven resource discovery service across a large number of educationally-relevant repositories via a combination of harvesting and real-time distributed searching.
The EdNA Online front-end portal provides a state of the art customisable discovery and collaboration experience for end users. It enables content and syndication of both the EdNA Online database content services and external content sources to be combined in a powerful and personalised interface. The user has been given the ability to control the choice of information and application services.
The re-engineered EdNA is being implemented using open source products where
applicable.
[HREF1] McKenny, Carol (2002). EdNA Online: strategic directions for customer focused resource discovery
[HREF2] EdNA Metadata Standard V1.1 http://metadata.edna.edu.au/
[HREF3] The EdNA Metadata Standard http://www.educationau.edu.au/papers/edna_metadata.pdf
[HREF4] An Example of Web Service Adaptation to Support B2B Integration http://ausweb.scu.edu.au/aw02/papers/refereed/smith2/paper.html
[HREF5] The Evolution of UDDI UDDI.org White Paper http://www.uddi.org/pubs/the_evolution_of_uddi_20020719.pdf
[HREF6] Building Online Communities for Professional Networks http://www.educationau.edu.au/globalsummit/papers/jbowes.htm
[HREF7] M. Nottingham (2002). "RSS Tutorial for Content Publishers and Webmasters", http://www.mnot.net/rss/tutorial.