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Towards more appropriate and friendly computerised extension tools - wiregrass control economics advisor - an example

A.F. Doss

NSW Agriculture, Agricultural Research Centre, RMB 944, Tamworth NSW 2340

The personal computer can be a useful extension tool for agriculture when combined with software that has been thoughtfully designed in consultation with the user. Certain agricultural problems lend themselves to solution by the computer. Others are clearly better suited to alternative media.

While formal methods for evaluating candidates for computer applications exist (2), consideration of some simple criteria may be sufficient. Is the application based on tedious calculations, a simulation, or the navigation of a complex logical pathway? Does it need to access large data sets? Does the subject domain have clear boundaries? Does the subject really need to be communicated? Are there sufficient staff and resources available to develop the software, to verify it, to maintain it and to use it? Are those staff committed to, and enthusiastic about, the software? Will there be an acceptable agronomic, social or financial return on the resources invested in its development? The answers to these will often be subjective but they can stimulate an objective decision.

On the slopes and tablelands of northern NSW, wiregrass, Aristida ramosa, reduces stocking rates, causes ill-thrift in animals, and contaminates wool (1). The Wiregrass Control Economics Advisor (WCEA), a computer program, provides cash flow and gross margin analyses of two methods of wiregrass control. Because these analyses use repetitive calculations, require the storage of large amounts of information, and illustrates the financial benefits of a desirable agronomic practice, a well designed computer program was seen as the best method for using them as an extension tool.

The WCEA replaces a spreadsheet application, WIREMAN, which was not well received by extension staff. WIREMAN required a high level of computer literacy, depended on the installation of an expensive licensed spreadsheet, provided limited on-line help, and required a great deal of user input. Each of these factors can contribute to user anxiety (3), and may explain the failure of extension staff to embrace the technology. To avoid these obstacles, the WCEA includes an attractive interface, comprehensive 'help' facilities, and graphical summaries where suitable, and uses artificial intelligence to reduce user input. It contains user definable defaults of market dependent variables to allow simple program maintenance, and allows modifications to previous analyses. Research and extension officers were consulted frequently during its design to comment on its progress and make suggestions for the final version.

The program is now in use with officers of NSW Agriculture. Its usage is being recorded for evaluation. The ideas used in its design are being adapted to other computer programs under development.


Dadd, C.P., McCormick, L.H. and Lodge, G.M. 1989. Agfact P.2.5.28.

Slagle, J.R. and Wick, M.R. 1989. AI Applications 3, 21-31.

Smith, M.N. and Kotrlik, J.W. 1990. J. Extension (Wisconsin) 28, 14-16.

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