This information paper was written by the National Library of Australia to describe the scope and intent of four of Australia's national subject gateways: Agrigate , the Australian Virtual Engineering Library (AVEL) , EdNA Online - the website of the Education Network of Australia (EdNA) , and MetaChem .
The four criteria shaping subject gateway development were identified as an operational framework, standards & guidelines, quality of service delivery, and scope. They have been mapped to the characteristics of the Australian subject gateways as described below.
The characteristics were developed by the National Library of Australia to elicit information of maximum value to the inaugural IMesh workshop held in June 1999 . The information was provided by the subject gateway owners. Additional observations have been provided by the National Library in consultation with the gateway owners.
The framework was defined as "a comprehensive guide to what is available and where. This will be an essential tool for identifying resources that already exist and who to approach as potential partners." .
The development of the framework may be measured by examining:
- 1. gateway coverage,
- 2. the quantity of resources and their update strategies,
- 3. the percentage of Australian and non-Australian content,
- 4. the ability to cross-search gateways simultaneously,
- 5. current partners,
- 6. plans for expansion within Australia, and
- 7. planned international partnerships.
1. gateway coverage
Agrigate is an agricultural subject information gateway for resources, both online and offline, of high quality research materials.
The AVEL gateway comprises a database of quality sources of engineering and Information Technology information on the Web. Due to the practical and applied nature of their subject, the information needs and information seeking habits of engineers and information technology professionals often differ from other disciplines. AVEL is designed to help them save time and find relevant information on the Web quickly.
EdNA is a network in several senses. EdNA Online is a Website pointing to thousands of resources identified and contributed by Australian educators. It also networks the bodies responsible for Australian education. Discussions and noticeboards are offered on the site, making it a meta-network of Australian education practitioners. It services and creates communities of educators online - further networks. The site is organised around Australian curriculum, its tools are free to Australian educators and it is funded by the bodies responsible for education provision in Australia - all Australian governments. Through EdNA fora, the Australian education systems and sectors collaborate on a range of online education, communications and information technology issues - a powerful network.
MetaChem is a single Web-based focal point for access to chemistry information resources of all kinds. The gateway provides access to Internet information such as electronic chemistry publications and databases, research projects, data sources, software, online teaching modules, directories, and conferences.
The need for a complete set of subject gateways providing the research information landscape in Australia is still under discussion - synergies with international gateways need to be further explored to resist duplication of effort.
2. the quantity of resources and their update strategies
Agrigate: contains 150 items to August 1999; in 13 broad subject categories. Its update strategy is three-pronged: (a) use of the update information associated with the Web pages on the fly (a feature for identifying URL materials that have been modified as well and then send an alert back to the webmaster that attention is required); (b) notification by users; (c) use of the administrative review element and report functionality.
AVEL: has 100 items to August 1999. Gathering software is likely to be added at a later stage to pull in sites identified by accredited contributors. The update strategy will be three-pronged: (a) the use of the ADMIN Core to signal expired resources; (b) the use of a link package to identify broken links; (c) feedback from users.
EdNA Online has 8,500 evaluated items to August 1999; in 1,000 detailed categories. These evaluated sites form the basis from which a further 230,000 linked items are indexed. Its update strategy is an indexing process for the 230,000 sites identified above that is a cyclic, semi-automated process. Complementing this is a customised robot which has been developed to harvest metadata-enriched content from accredited contributors' websites.
MetaChem: has 645 items to August 1999. A gatherer has been used to pull in sites which already contain recognisable metadata. The addition of new resources is likely to slow down after the initial gateway establishment. Its update strategy consists of (a) software for broken link checking is being assessed; (b) random checks by contributors as a result of the selection process.
3. the percentage of Australian and non-Australian content
Agrigate is largely Australian at this point. Relationships with other gateways on other continents, such as AgNIC in the United States, will be implemented as links in the first instance.
AVEL will be largely Australian initially, but is also investigating the addition of resources for South East Asia and the Pacific Rim.
EdNA Online has global content, tailored to the target group. Statistics indicate around 63% Australian content, reflecting a focus on local content. An optimum mix of Australian and non-Australian resources has not yet been identified.
MetaChem has very little Australian content currently - local contributions are expected to increase as liaison with Chemistry Departments in Australian universities increases.
4. the ability to cross-search gateways simultaneously
Agrigate will examine the possibility of using Z39.50 in the future. In the interim, sites will be linked to until more items become available.
AVEL is considering the feasibility of mirroring EEVL in Australia. In addition, there are three possible cross-searching options:
(i) the use of HotOil with EEVL and EELS. No relevance ranking algorithm is applied by ranking one gateway against another. Rather, the results are interleaved by removing duplicates, and then listing the results alphabetically. (This is a simple option to apply when the ranking algorithms of individual sites are not accessible or are unknown.) The criteria for removing duplicates are: (a). If Web-based resources, a match on URLs; (b). If Z39.50 accessible (and therefore mostly print-based), then a match on ISBN/ISSN and title.
(ii) it is possible to activate three different searches simultaneously, using the query language expected by each database, then combining the results into one set. An extension to this is ranking:
(iii) in the EEVL software, results are ranked according to different criteria (due to the different software and records being searched, it is unfortunately impossible to rank them in exactly the same way), however the end product is usually to rank the most useful records first. The EEVL catalogue does not count the instances of search words (which may be random) but weights them according to where they appear.
EdNA Online is enabled by a combination of centralised searching through the transference of metadata from distributed sites or the addition of metadata to a central repository hosted by EdNA Online. Z39.50 searching is being considered as an enhancement, particularly by the higher education sector.
MetaChem is experimenting with the use of Sherlock (a MAC server tool) permits non-Z39.50 search and retrieval of distributed sources, including the gateway, library catalogues, and personal files . For international sites, mirroring is preferred in order to overcome network response time difficulties. This is more of an issue for MetaChem than the other Australian gateways given the high percentage of non-Australian resources. The decision should be based on knowledge of the target audience.
The need for an ability to conduct searches across gateways is based on an assumption that none of the gateways will host content. Rather they will host it as part of a separate service (and therefore the content will be linked to in the same way as if it were remote) where the content is instantly accessible.
The ability to support other strategies, such as mirroring of gateway resources or centralised searching options have not yet been decided, but issues such as best response times, technical content maintenance, refresh/update rates and synchronisation of data transfer will need to be considered by the gateway owners. The needs of target audiences should be reflected in the decision to incorporate other gateways' resources. As a secondary process, the gateways would like to explore the viability of delivering content by other technical means such as intelligent agents.
The Australian gateways utilise the Dublin Core metadata standard as a baseline and this could be used as a data exchange format to support interoperability. Agrigate and EdNA Online are underpinned by relational database technology, MetaChem and AVEL are using tailored versions of the Distributed Systems Technology Centre's HotMeta product . Queries are managed via HTTP. ROADS software is used in Australia, but not by these subject gateways.
5. current partners
Agrigate's partners are the University Libraries of Melbourne (lead), Adelaide, Queensland and the Commonwealth Scientific & Industrial Research Organisation (CSIRO).
AVEL's partners are the Universities of Queensland (lead), Queensland University of Technology, Melbourne, University of New South Wales, and Monash University, the DSTC, the Institution of Engineers in Australia, and the Centre for Mining Technology and Equipment (CMTE).
EdNA Online is owned by the Vice-Chancellors of all Higher Education institutions, the Commonwealth Department of Education, Training and Youth Affairs (DETYA), CEO's of all State and Territory Systems, and all Education and Training Ministers. Managed by Education.Au Limited http://www.educationau.edu.au, a non-profit company owned by MCEETYA (Ministerial Council on Employment, Education, Training, and Youth Affairs).
MetaChem's partners are the University of New South Wales (lead), including the Australian Defence Force Academy (host); the Universities of Melbourne, Monash, Sydney, Macquarie, Newcastle, Queensland, the Australian National University, Royal Melbourne Institute of Technology, and the DSTC.
6. plans for expansion within Australia
Agrigate is arranging discussions for potential collaboration with State-based Departments of Agriculture and other agricultural centres.
AVEL has been approached by several other Australian universities: the University of Western Australia, the Royal Melbourne Institute of Technology, and the University of Adelaide. These are still under consideration. A link to the Australian Digital Theses project will be considered .
EdNA Online provides a 'meta-network' for all education networks and gateways. The subject gateways initiatives within Australia have a natural affinity, and EdNA provides them with an opportunity for added value through aggregation.
The MetaChem gateway is considering a link to the Australian Digital Theses project .
7. planned international partnerships
Agrigate's partnerships are still being explored. An e-mail exchange has begun with NOVAGate (Scandinavia) and AgNIC (United States). There has been further dialogue with the Centre for Agriculture and Biosciences International (CABI) re the subject areas on their website. Potential connections with the US-based National Agricultural Library and Agricola will also be pursued.
AVEL has commenced collaboration with the Edinburgh Engineering Virtual Library (EEVL); is considering possible cross-searching with EELS, an approach to Project ISAAC is planned, and expansion into South East Asia and Hong Kong is also being considered.
EdNA Online is in discussion with the SCOUT Project's proposed ISAAC Network .
There are several international subject gateways available for chemistry research. MetaChem has made contact with its German equivalent at http://destille.chemie.de:8080/metachem and plans to liaise with BUBL and Project ISAAC .
Within Australia, each gateway has been strengthened by its collaborative nature. In addition, IMesh is considered to be essential for development and continued synergy possible with strong partnerships. The Australian projects are considered national by virtue of the breadth of their participants, but are committed to both sharing and learning from the expertise and experience of the longer-established gateways in other countries.
The guidelines (including Evaluation) were defined as: "the wealth of experience in creating and managing Internet gateways, and the costs of these activities, which exists in the community." .
The standards and guidelines are reflected in:
- 8. the metadata schemas used for resource description,
- 9. solutions for technical issues arising in the establishment of the gateways, and
- 10. the evaluation criteria for the gateways.
8. the metadata schemas used for resource description
Agrigate's schema includes the Dublin Core, the Australian Government Locator Service (AGLS), EdNA-specific elements, AGRIGATE-specific elements, the A-Core; and Alta Vista style metadata for the home page. 
AVEL uses the Dublin Core, AGLS, and the A-Core. In addition, it will mirror the EEVL standard where possible. AltaVista-style metadata and the PICS schemas have also been included. 
EdNA Online uses Dublin Core and EdNA-specific elements. AGLS is planned for addition in 1999. EdNA has also reconvened its metadata working group to investigate harmonisation with the IMS schema, and specifically address the pedagogy element. 
MetaChem uses the Dublin Core, AGLS, EdNA-specific elements, the A-Core, and PICS-style schemas on the home page. AltaVista-style metadata is applied to the home page. Chemistry specific qualifiers are under discussion. The DC-Chem schema, proposed by Henry Rzepa, of the Imperial College Cambridge, is also being investigated. 
Each of the schemas is based on the Dublin Core. Although this standard permits the elements to be optional, each gateway has chosen to recommend a minimum subset mandatory, to ensure the consistency of search results.
The addition of metadata to support the Platform for Internet Content Selection (PICS) ratings scheme has been raised as a concern. A suggested recommendation was that capacity for a single element or a standard HTML statement be provided with a content rating equivalent of 'no blocking required', which would be applied to all resources. It may be necessary to provide an HTML statement for each ratings system to be supported in Australia, for example, RSACi, SafeSurf and www.adequate.com.
9. solutions for technical issues arising in the establishment of the gateways
Agrigate is aware that competition for resources on a LAN network could prove to be a bottleneck in accessing data in the future. Current systems are fine, in that Melbourne University maintains a
large institutional network within which Agrigate is located. Other institutions may find competition for resources to be a concern.
AVEL is building on the experiences of the University of Queensland where training people in the use of an editor has not been easy. The best success has been achieved with the use of the State Library of Tasmania's generic editor that permits full-text content creation simultaneously with its metadata. However, this tool is restricted to embedding the metadata in the original resource or a digital surrogate of the resource.
Currently, EdNA Online development work is focused on a closer integration of search and browse information retrieval methods which is also being complemented by customisation tailored to specific groups in the first instance and then individual user profiling. The technical architecture proposals that form standards within the IMS (Instructional Management systems) project http://www.imsproject.org are being watched closely. EdNA Online has also adopted a distributed administration model that is in transition toward LDAP implementation. Metadata tools are being developed to assist stakeholders in enriching their own sites by integrating creation processes into workflows wherever possible.
MetaChem has had some difficulty in establishing creation tools suitable for Apple MAC platforms.
10. the evaluation criteria for the gateways
Agrigate's evaluation criteria are:
- (i) researcher perception of Agrigate, its usefulness for finding resources of value to their work, and the ease of use of the interface;
- (ii) the 'hits' measures for the site including amount of use of defined categories and searching facilities;
- (iii) the range of material types that are included in the gateway, such as documents, data sets, visual information [mapping, charts, illustrations], multi-media formats;
- (iv) the identification of categories not included in the pilot that would be of benefit in future expansion of the site;
- (v) ease of maintenance and reliability of the software; and
- (vi) perceptions of the reference group regarding the governance and management model used for the development, implementation, and future direction.
AVEL's evaluation is scheduled for 2000. The criteria are under development.
EdNA Online has set the following criteria:
- (i) the close matching of the 'natural architecture' of the enabling technology (the Web) with the architecture of the stakeholder base;
- (ii) a commitment to facilitating bottom-up 'ownership' of the process of building the service;
- (iii) a commitment to community-building;
- (iv) quality assurance standards; and
- (v) making explicit the potential to minimise duplication of effort.
MetaChem is planning a full evaluation later in 1999. The following criteria were identified at the start of the project:
- (i) excellence of the researchers and the research activity to be supported by the Project;
- (ii) the effectiveness of cooperative arrangements between institutions including access and resource sharing;
- (iii) financial commitment to the proposal by each institution; and
- (iv) the need and level of demand for the proposed equipment or facilities in Australia.
The quality of service delivery has been defined as: "issues regarding quality assessment and agreements over quality criteria." 
The quality of service delivery is enhanced by applying:
- 1. selection criteria for gateway content, and
- 2. thesauri - for metadata creation, for searching and browsing by keyword.
1. selection criteria for gateway content
Agrigate's selection criteria cover the areas of content; scope and treatment; format; arrangement and special reasons that make a resource unique and valuable for exposure .
AVEL's criteria are based in principle on the Agrigate categories for inclusion, and the AVEL-specific criteria address core engineering and IT topics .
EdNA involves collaboration between schools, the Vocational Education & Training (VET) sector, & Higher Education. At this stage, the schools & VET sectors have developed their own sector-specific quality assurance standards. The university sector assumes that quality assurance operates at the individual institutional level .
MetaChem selection is based on the experience and knowledge of the science librarians and chemists assessing the resources.
The selection criteria were determined collaboratively by the participants of each Australian gateway project, and are based on their collective experience as librarians and subject matter experts. In addition, the Agrigate project conducted extensive literature reviews of the success factors of Web sites with long-term viability. The selection criteria of similar U.K.-based subject gateways were also examined, including EEVL, BUBL, OMNI, SOSIG (DESIRE), and AHDS.
In addition to the selection criteria, each gateway utilises a combined human/system editorial or gatekeeper function to control the quality of resources nominated for inclusion by non-participants. Suggestions are provided via standard templates which encourage the creation of a modicum of metadata.
2. thesauri - for metadata creation, for searching and browsing by keyword
Agrigate applies both the CAB International Agriculture Thesaurus, from the UK; and Agterms, developed by the Kondinin Group, which is an Australian extension to CABI.
The thesauri are used for both metadata creation, and search/browse access. A full list of the terms used, combined with a quick-find index of the type A-B-C, also gives a snapshot of gateway coverage.
AVEL will base its thesaurus application on the EEVL thesaurus, and strengthen it in the area of specific Australian engineering industries such as mining. The use of the Library of Congress Subject Headings is also being considered.
EdNA Online is considering the use of the Australian SCIS (Schools Catalogue Information Service), for both metadata creation and navigation. The higher education sector is also actively investigating the potential to broaden thesaurus usage and is considering usage of the thesaurus provided by the Australian Council for Educational Research. The category tree (of evaluated items) is classified according to 1000 categories developed collaboratively, and, as such, acts as a mini multi-faceted thesaurus. Work is underway to extract from this a finer grained superset of categories from which an EdNA thesaurus (one which caters to all sectoral needs) may emerge.
MetaChem is considering the use of Chemical Abstracts; and the BUBL categorisation, for both metadata creation and navigation. Concerns re the application of any thesaurus chosen are consistency of use and sustainability.
Scope was defined to reflect the expected audience for the gateway services, as follows: "most resources so far have been collected for use in research in higher education. Some countries want resources which are relevant and accessible to all levels of education, not just higher education. Mechanisms for widening the user base successfully and the funding implications of these additional activities will need to be fully articulated." 
The scope of the subject gateway projects is determined by:
- 1. the types of resources described,
- 2. the intended gateway audience,
- 3. promotional activities,
- 4. guidelines for linking to the gateways, and
- 5. long-term strategies.
1. the types of resources described
Agrigate provides web sites as its highest priority; other electronically available information sources as a second priority (databases, telnet sites, ftp stores); niche information
solicited from Australian researchers third (information not previously placed on web sites); and non-electronic materials last or later (real objects such as specimen collections, printed materials).
AVEL will provide access to all material types including commercial sites. As well as library catalogues, company Web pages, and e-journals, AVEL will include such resources as product information, patent information, industry news, standards and specifications, technical data, software, and physical property data.
EdNA Online includes value-added (evaluated), educationally useful content (websites & pages) for teaching & learning purposes; research-based resources; aggregated indexes; information about Australian education and training, both generally & specifically related to each sector; archived discussion lists; noticeboards of events & collaborative projects; and, services such as news concerning education.
MetaChem places web sites as a top priority; other electronically available information sources as a second priority (databases, telnet sites, ftp stores); niche information solicited from Australian researchers third (information not previously placed on web sites); electronic theses available through the Australian Digital Theses Project Web site; and non-electronic materials last or later (research reports, print-based theses etc).
Each gateway has predominantly focused on the discovery of electronic resources which may be hosted by the participants, or hosted by another site where there are no access or copyright restrictions. Agrigate, MetaChem, and EdNA Online have chosen not to point to library catalogues, print materials (unless rare or otherwise inaccessible), or commercial information suppliers. AVEL will provide links to the latter source.
MetaChem and AVEL are also exploring the possibility of including links to chemists and engineers in the field, as in some cases, contacts rather than research are the more important connections.
In Agrigate, each partner organisation is allocated a subject area to identify resources in the area, and ensure an even spread of specific subject matter as much as possible.
For EdNA Online, resource discovery and information retrieval are complemented by interactive services and network facilitation.
2. the intended gateway audience
Agrigate supports those participating in Australian agricultural research and those interested in research areas being pursued in Australia.
AVEL's clients are (in priority order) researchers in universities, research centres, companies, and government departments; undergraduate and postgraduate students; engineers and IT professionals; libraries; overseas researchers; general public.
EdNA Online encompasses the schools, vocational education and training, adult community education and higher education sectors.
MetaChem provides resources for chemistry researchers, both public and private; research & development sectors; policy managers.
3. promotional activities
Agrigate has deployed the following promotional strategy:
- (a) presentations of papers at national IT, and library conferences;
- (b) notification to agricultural, metadata and IMesh discussion lists;
- (c) articles in agricultural journals such as AGRIIA; and
- (d) inclusion of the Web site address in international search engines [Yahoo, Altavista, etc.], as well as major Library websites' subject lists.
Agrigate has recently been selected and reviewed in the Scout Report , and in the Internet Resources Newsletter .
AVEL's promotional strategy will be developed over the next few months, as the gateway develops. This will include representation at engineering conferences such as AAEE. It was recently described in Ariadne . In addition, engineering students at the University of Queensland are instructed on the use of authoritative sites such as EEVL as part of their coursework.
EdNA Online provides a 'What's New' service and News & Views features offers a weekly reminder of the validity of the service. Within EdNA itself a marketing group exists and activities are planned right throughout the year. EdNA has also created 6,000 CD-ROMs for distribution to schools.
MetaChem was released to Professors and Heads of Departments of Chemistry (PHODS) in January 1999, and presented to the Royal Australian Chemical Institute at their annual council meeting in May 1999.
All of the gateways are promoted through two National Library of Australia sites: MetaMatters , and the Australian Libraries Gateway . The latter has adapted the PINAKES site as a model , with the addition of draft selection criteria for inclusion.
4. guidelines for linking to the gateways
Agrigate is considering the following options. (a) a standard email to selected sites, with some key pieces of information that indicate the presence of the gateway and its suitability for linking; and (b) an acknowledgement of a resource selected for inclusion in Agrigate, by sending a note to the resource owner telling them their material has been included in Agrigate, inviting them to take a look and also sending along the Agrigate icon, to incorporate in their page as a 'badge of honour' that says their materials are in Agrigate.
AVEL is exploring possible strategies such as cross-gateway searching.
EdNA Online derives added value and mutual benefit through ongoing negotiation.
MetaChem has adopted a practice of acknowledgement similar to Agrigate's processes.
Based on his earlier successes and failures with subject information networks, Professor David Green of Charles Sturt University has suggested accreditation as the most effective means of encouraging relationships between gateways. This would be effected along the lines of the Agrigate processes outlined above.
Relationships may also be mandated by Australian government policy. For example, the Australian Government Locator Service (AGLS) is an initiative of Australian governments across all three tiers: local, state and federal . The AGLS metadata set is the standard schema for describing Australian government resources, to facilitate their discovery. The subject gateway owners need to consider the provision AGLS metadata to the home pages for their services, but not the resources contained within the gateway, in order to meet this requirement.
5. long-term strategies
Agrigate commenced in 1998, and additional Australian Research Council funding was received in 1999. The partnership between all participants and sponsors will remain to sustain the gateway beyond existing project funding. A business plan is planned for release at the end of 1999.
AVEL commenced in 1999. Collaboration will be sought from commercial ventures to ensure future funding, for example, with Engineering Information Inc.
EdNA Online has ongoing funding support by the Commonwealth Department of Education, Training and Youth Affairs, and all State and Territory Education Departments. Each year, Education.Au develops a Business Plan for the coming year. Other revenue streams to support the service will become operative by July 1999.
The partnership established between all MetaChem participants and sponsors will remain to sustain the gateway beyond existing project funding.
The subject gateway owners do not intend to apply (electronic) commerce functionality to any of the gateways at this time. Copyright management of the resources described will be achieved through the application of metadata. There is no intention by the gateway owners to archive the full-text content of resources.
In addition to the observations discussed above, the Australian subject gateways are also keen to address issues which, when solved, will help to solidify the investments made. Two major issues already identified are firstly, the sustainability of the gateways - how to ensure longevity and the return on investment - and secondly, the intellectual property rights associated with resource provision, i.e., how to protect the investment in metadata and metadata schemas while continuing to enable cooperation.
Inspired by the IMesh workshop, the National Library of Australia is also trying to develop a sustainable national framework for subject gateway development . As the subject gateways stabilise, Australia looks forward to resolving the issues with the assistance of national and international partners providing resource discovery services.