This paper examines a set of applications of data communications, which are often described by the generic term "computer mediated communications" (Mason and Kaye, 1989). The first perspective to be described is the user's view of the interface to the desired services, keeping in mind the functional simplicity of the interfaces or environments we encounter as users of automatic tellers and telephones. However, we do have to go further and look at some of the underlying details of technologies, organisation and management for computer mediated communications, for two reasons. Firstly, the attainment of a user friendly interface for the complex set of services available in computer mediated communications for education and training is somewhat more difficult than learning how to use the very simple keypads and commands for operating telephones and automatic tellers. Secondly, decisions about organising and managing computer mediated communications for education and training are often made in the context of insufficient knowledge of network services and networks, and how these areas interact with the users and their purposes.
Before beginning, a note the approach in the first section, which describes my own "environment" for everyday, routine use of computer mediated communications. The platform in front of me is usually the Macintosh LC at my personal desk, but sometimes it is another type of Apple computer, or a DOS or Windows personal computer. Although for convenience the examples I cite are all derived from my Mac LC, software which delivers comparable easy to use interfaces is available now, or is becoming available, for DOS and Windows platforms. The main point is that the interface, regardless of whether it is delivered on an Apple, DOS or Windows desktop can be, and should be, a very much easier to use interface than has been the case in the past.
Subsequent sections build upon this main point. What are the characteristics of network services and networks which enable a user friendly interface? How are these characteristics related to education and training purposes? How do we derive the best advantages from computer mediated communications? These are important questions at the present time, in view of the impetus created by the rapid expansion of AARNet (the Australian and Academic Research Network) (AARNet, 1992; AVCC, 1992; Campus, 1991), and some Federal Government initiatives to obtain greater use of this medium for education and training purposes (DEET, 1992a; DEET, 1992b; DPIE, 1992).
The second set of examples illustrate NewsWatcher, a utility for reading Internet News. Figure 5 is the status window displayed whilst NewsWatcher is fetching the subject and author headings for a selected newsgroup, in this case "aus.mac". As I have an Ethernet connection to Murdoch University's network news host, transfers of headers and text is relatively rapid.
The third set of examples illustrate Fetch, a utility for facilitating the use of the file transfer protocol or "ftp", which is part of the TCP/IP set of protocols (defined later in this paper). Figure 9 shows Fetch in action. I needed a copy of the file ISDN_numbers.txt, which Betty Walsh maintains as part of her External Studies Unit responsibilities in video conferencing operations. This file gives ISDN numbers, contact persons, phone and fax numbers, and email addresses for all or nearly all educational video conferencing sites in Australia. The Fetch window shows the file, which resides on the host csuvax1.murdoch.edu.au, selected for download to my Mac LC by the technique known as "anonymous ftp", which is accessible to any user of AARNet .
The window behind the Fetch window in Figure 9 shows my csuvax1 status, whilst in the top right hand corner appears the "Send" button for a Eudora message reply window, which I had open in order to paste ISDN_numbers.txt into it. The Eudora reply was to help a correspondent at Charles Sturt University Riverina Campus who had encountered some difficulty in obtaining it by ftp. Figure 9 may seem like a jungle, with seven windows open, but it is not a problem for users with basic experience, such as that acquired through using any of the common word processors for Macintosh.
However, there is a catch to all of this. The user's access to very friendly and easy to use interfaces is very dependent upon a great deal of work in organisation and implementation of an infrastructure which makes it possible. Table 1 summarises the position of Eudora, NewsWatcher, Fetch and some other utilities by categorising them as clients to a server or host with specific protocols implemented. The remainder of this paper is devoted to examining these and some other aspects of network services and networks which are essential for creating ease of use at the desktop.
Before moving on to the wider topics, there is one further great point about Eudora, NewsWatcher, Fetch and others in Table 1. All are public domain items, which you can copy and use for no charge at all. Furthermore, certain Apple proprietary extensions to the Macintosh operating system which are essential for running Eudora, NewsWatcher and Fetch are also now in the public domain. All are obtainable by anonymous ftp from a number of sites including archie.au, AARNet's archive for public domain software (AARNet, 1992). Similar public domain and commercial products are becoming available for users of Microsoft's Windows platform (Windows PCs are often referred to by the misleading term "IBM compatibles" although this operating system is not an IBM system).
|Client software||Server or host |
|Eudora v1.3b34||POP (Post Office Protocol) and other protocols||Email utility - fetch, despatch, in, out and other mailboxes, edit, aliases, etc.|
|Network News Transfer|
Protocol and others
|News utility - select groups, read, edit, follow up, edit, post new article, etc.|
|Fetch v2.1b4||File Transfer Protocol|
and anonymous login
|Utility to facilitate use of FTP - connect, receive, send, change directory, etc.|
|Telnet and others|
in the TCP/IP set
|VT100 terminal emulation for remote login or telnet.|
|MacGopher||Gopher server||Information retrieval service.|
The reason for the development and the popularity of client server implementations is that these are much easier to use, compared with the typical command line and editing capabilities offered by network hosts. For example, a user could undertake email operations such as read a message, reply to a message, and so on, using the "Mail" program available on a typical Unix host, or mail handling aids such as "Elm" or "Pine" which are often available on such hosts. However, the great majority of users find that commands for email actions and the host's editing capabilities are very much more difficult to operate, compared with the kinds of commands and actions which they are familiar with as users of personal computer software such as word processors. This is especially the case with users who are accustomed to the speed and intuitive nature of a "wimp" environment (windows, icons, mouse, pull down menus) as provided by Macintosh, Windows and many DOS programs. I think that the great majority of personal computer users resent having unnecessary extra learning tasks thrust upon them.
Client server implementations are dependent upon the availability of agreed protocols for communications between computers. Broadly, these allow one to specify a process for network communications which is independent of the hardware and software used by others. Complex data communication systems use a set or family of cooperative protocols, each with a specified functional relationship to the others and generally describable by layered models (Comer, 1988; Black, 1987). The key set of protocols we are concerned with is TCP/IP, named after one of its components, Transmission Control Protocol, and its more general family name, Internet Protocol (Comer, 1988; AARNet, 1992). AARNet's traffic is almost wholly TCP/IP, although other protocols may be in simultaneous use also on a local basis. For example, External Studies uses Appletalk for local communications to in house printers and file servers, whilst simultaneously using the same Ethernet to carry TCP/IP for Eudora, NewsWatcher, Fetch and other functions. Users do not need to know anything about these details because software handles the selection of protocols automatically.
TCP/IP specifications are in the public domain. Though not an official international standard, TCP/IP is very widely supported by all the major vendors in computing and networking, by a varied range of gateways into other systems, and by a wide array of software in the public domain for Unix, Macintosh, DOS and Windows, as illustrated by the examples of Eudora, NewsWatcher and Fetch and the corresponding server software. The concepts of independence from proprietary protocols and network hardware, and availability from a number of competing vendors are very significant reasons for the popularity of TCP/IP as a basis for computer communications.
Client server implementations very often assume that the client and server are both connected to an Ethernet. This is much less expensive than it used to be. Under Murdoch University's networking policy, the cost to the Unit's budget for purchasing each Ethernet port including cabling and wall socket is $700, to which must be added the cost of Ethernet hardware for each Apple machine, currently about $325. The University's internal charge for Ethernet ports represents a full cost recovery for internal unshielded twisted pair cabling and Ethernet 10 base T repeaters within a building, whilst the inter-building fibre optic links are centrally funded. Hosts such as csuvax1 are centrally funded and are relatively economical, partly because the communications software implemented on them is also from the public domain.
However, there are some very important circumstances in which an Ethernet is not available to the user, for example users located at home or in small centres without a local area network (LAN). In the case of telephone line and modem dialup to a network host, which may be the only access available to such users, the implementation of user friendly tools like Eudora is generally more difficult, and may require a significant amount of expertise and further development work.
The basis from which TCP/IP originated is "internetworking", the linking of separate networks to one another to create networks of networks. The typical connection to AARNet is between an organisation's own network, for example a campus LAN, and a state or regional node, which is linked further to other regional or national nodes. Internetworking with TCP/IP means that the vast majority of the network resources reside with the individual networks and computer hosts owned and controlled by the members of AARNet, which is an important feature in relation to strategies for obtaining greater use of AARNet and computer mediated communications for education and training purposes.
AARNet delivers a range of applications of computer communications which are independent of the types of physical link and end user hardware and software, provided that all are in conformity with the TCP/IP protocol set. The transmission paths or network architecture carrying the TCP/IP traffic may include one or more of Ethernet, ISDN, Megalinks, Digital Data Services, X25 packet switched, serial links, microwave links, satellite hops or others, even ordinary telephone lines. The end user does not need to know these details, which are matters for specialists in network systems engineering.
There are many other models for client server implementations. For example, Pegasus, a private provider of email, Netnews, AARNet and Internet access and other services has produced client software to assist users of dialup connections to Pegasus. There are many proprietary implementations of client server models, including email services such as Mail Perfect which is part of the Word Perfect suite of office software. Telecom's Keylink email service makes available the Desklink software, which is easier to use than the command line environment of Keylink's host. However, very few of the proprietary implementations can compete with the low cost, huge user base, breadth of services and flexibility available from the combination of TCP/IP based implementations and AARNet connection.
AARNet provides an infrastructure which developers of open learning and distance education (Castro, 1990) can use without having to design and implement their own network for the basic services listed in Table 2. However, developers of these services are needed for the vitally important role of implementing applications which are directly relevant to the needs of end users, for example, tutorial services using email, information services using Netnews or listservers, distribution of print and computer assisted learning materials by anonymous ftp, retrieval services based on WAIS or gopher concepts, and so on.
Considerable work is required at the institutional level to organise student access to AARNet, for example through learning network centre or home or workplace facilities, using dialup or direct connections to an institution or a private provider of AARNet access (Atkinson, 1992b; Atkinson and Castro, 1991). Further work is required to make available user friendly interfaces at the standard of the Eudora, NewsWatcher and Fetch examples described above.
|Electronic mail||The most widely used service, constituting about 11% of AARNet traffic. Over 12 million users world wide.|
|Netnews||Divided into about 1500 newsgroups. Contributions are distributed automatically world wide. Used to obtain information and seek contacts in a wide variety of technical and non-technical topics. About 6% of AARNet traffic.|
|File transfer||Network transfer for any files. Anonymous ftp (file transfer protocol) used for distributing documents and software. About 35% of AARNet traffic.|
|Remote login||Access other computers on the network, eg. data bases, supercomputers. About 9% of AARNet traffic.|
|Information services||File server publishing, directories, electronic journals, online library catalogues and other structured services which assist the user to locate information.|
|Retrieval services||Recent developments of information retrieval tools which enable users to specify plain language commands to search networks and retrieve the desired information, eg WAIS (Wide Area Information Service) and Gopher servers.|
As a network of networks and a vehicle for regional, national and international communications, AARNet carries services which are available to every user anytime and anywhere on the networks, and can be originated anytime from anywhere on the networks. Computer mediated communication is a highly supportive tool for enhancing the delivery of open learning and distance education, because it can be used very readily for one to one, class group, peer group and "broadcast" forms of communications, for information retrieval and for courseware distribution, whilst retaining individual freedom of choice in the scheduling of learning activities. This medium offers interaction with a peer group, without the need to know beforehand any persons in that peer group, or their location.
Developers of open learning and distance education applications carried by AARNet do not have to worry about scheduling in the way that is the case with audio, audiographic and video conferencing or television broadcasting. It is not surprising that the Open Learning Initiative (DEET, 1992c) has perceived computer mediated communications to be a vitally important medium (DEET, 1992b). It is also a very effective medium for communications relating to professional development, courseware development and many other activities which are essential in the infrastructures for education and training, especially in the case of open learning and distance education modes.
Another important concept exemplified by AARNet is the scope for decentralised approaches in which a number of providers support a particular application. For example, the conduct of clearing house and database functions (DEET, 1992a) can be decentralised over AARNet by use of the gopher server concept, whereby the user interacts with gopher client software and sees a single database, responsive to plain language commands.
AARNet is not a relevant basis at present for building audiographic teleconferencing systems, such as those using Apple based Electronic Classroom or DOS based Telewriter and GTCS. Typically, audiographic applications use their own proprietary protocols over public switched telephone network connections made as required for each teleconference session, in contrast to the permanent private network connections between local networks and hosts which are the usual basis for operating TCP/IP communications protocols. However, if based upon ISDN semipermanents, there is scope for audiographic applications to coexist on the same channel with a connection to hosts which are further connected to AARNet, by means of digital telephone handsets and multiplexers to partition the 64 kb/s capacity into subchannels for voice, audiographic data, and TCP/IP traffic.
. . . foster and support the development of a number of community managed demonstration telecentres to explore the role of new information technologies in assisting the economic and community development of the districts in which they are located. The aim is to show the uses to which modern computers and related informational technology can be put to improve the economic, social, educational and training opportunities of that community, through better information access and communications. The expansion of employment and business opportunities through the use of these technologies is a key objective of the program (DPIE, 1992).One method for analysing the requirements for successful operation of a telecentre in relation to computers and information technologies is a "layered model", represented in Table 3. This model is a brief sketch of a potential strategy. The three layers correspond broadly to different sorts of organisations, functions and scales of operation.
|Local community Telecentre||Provide coordinator, local business plan and program, accommodation and local equipment.|
|Network services||Provide economic, social, educational and training opportunities and information.|
|Network||Provide computer hosts or servers for network services, arrange data communications capabilities and training for local community telecentres to access these.|
The model indicates that providers of information and other network services, and providers of a network infrastructure, are essential complements to the telecentre's local facilities and support. Some organisations may be able to provide services in two layers, for example a TAFE sponsored telecentre (layer 1) with TAFE courses (a component of layer 2), or university courses (a component of layer 2) and access to an AARNet connected host (layer 3), but in general no single organisation will be able to provide all three layers.
As a brief sketch, this model does not indicate how telecentres could relate to many other initiatives in progress. These include, for example, Queensland's Open Learning Network, WA's Learning Network Centres (McGregor and Latchem, 1991; McGregor, 1992), the Open Learning Technology Corporation (AEC, 1991; Spring, 1992; Atkinson, 1992e), the Open Learning Initiative (DEET, 1992b; DEET, 1992c), the ADEnet Project (Atkinson and Castro, 1991), plans by a number of universities and TAFEs to expand their use of "flexible learning centres" or "study centres", TAFE's adoption of AARNet (Atkinson, 1992d) and the continuing rapid expansion of AARNet as indicated in its Business Plan (AVCC, 1992).
The "network layer" is likely to be a key factor in the viability of the other layers. As a broad strategy, connection to AARNet is an obvious priority, because that offers open access networking to a wide range of existing and potential new services from the university sector, and from the TAFE sector also as it adopts AARNet. Unfortunately, state and federal government departments are typically in private network environments and therefore have not developed servers for anonymous ftp and other concepts inherent in open access information technology. Telecom cannot offer any equivalent to AARNet and Internet.
A number of different designs may be relevant for a network infrastructure which could link telecentres with AARNet. Some are outlined in AARNet's Affiliate Membership documentation (AARNet, 1992). Bearing in mind the need for the end user to be given a user friendly screen environment and a wide choice of network services, the most appropriate strategy for small telecentres may be operating Eudora, NewsWatcher and Fetch, or their counterparts for DOS or Windows, to access a host at the nearest AARNet connected campus. The physical connection may be an ordinary STD telephone call, dialled up only when transmissions are required, using a high speed V32bis modem with error correction and data compression (Fist, 1992). It is likely that high speed modems and automation of communications to the nearest host, by means of Eudora and similar utilities, would reduce the STD connect time charges to levels significantly lower than the overall costs of using Austpac, Telecom's public X25 data transmission service.
On a larger scale permitting multi-user operations, a local Ethernet and a small router (Hindin, 1992) to link between the Ethernet and a V.32bis modem may be appropriate. Another option is to utilise a small local Unix host, which undertakes regular and brief dialup calls to an AARNet connected gateway host, to exchange mail and news. This option is functionally similar to the Fidonet system, which is used extensively for low cost, single user bulletin board systems, and has been trialled in some secondary schools (Chandler, Gesthuizen and Clement, 1992). Private providers of hosts and access to AARNet, such as Dialix in Perth and Sydney, may be able to secure a role.
Thus there are a range of methods by which network services and network connectivity could be extended to the proposed telecentres. In establishing telecentres, the importance of adequate trialling of the different methods for providing network services through AARNet connectivity should be fully recognised. Although the basic framework and supporting technologies are available for layers 2. and 3. in the model above, a considerable and detailed design effort will be required to implement an efficient, easy to use and economical service to layer 1. In order to make information technology a reality for a telecentre, the information part needs assured sources, and the technology part needs to provide the network which communicates with those sources.
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Dr Roger Atkinson is Acting Director of External Studies at Murdoch University, with 14 years' experience in distance education. Recent activities in research and development include convening the DEET Communications Link Project, directing the Reserve Fund Video Conferencing Project at Murdoch, and coordinating the Reserve Fund ADEnet Project for improved computer communications in distance education.
Please cite this paper as:Atkinson, R. (1992). Some developments in computer mediated communications. In J. Herrington (ed), Distance education: Future visions, p51-74. Perth: WADEC. http://www.roger-atkinson.id.au/pubs/devcmc92/devcmc92.html
Dr Roger Atkinson
Academic Services Unit
Murdoch WA 6150, Australia