Introduction
Those unfamiliar with DIAGNOSIS should click
here for a quick explanation of what the software does. Don't
let the name fool you. DIAGNOSIS is not a diagnostic expert
system. The Educational Value of DIAGNOSIS Educational experts generally agree that incorporating a problem-solving approach in instructional design can facilitate learning (for some good reference material on this subject see this document by educationalist David Merrill ). DIAGNOSIS presents students with a problem to solve, captures their diagnosis, justification and solution and provides feedback. Students generally react very positively to the exercises. They are forced to integrate and synthesise material learned elsewhere in other courses (soil science, plant physiology, entomology etc.) thereby looking at a problem in a holistic way. In this way they learn the "art" of diagnosis (Grogan, 1981). The exercises seem to work best when the students undertake them in pairs or small groups. This way they can bounce ideas off each other, working and communicating as a team. Another useful exercise is to get students to actually construct scenarios themselves, then get other students to play and critique them. Just as having to teach material forces a new teacher to learn it well, constructing scenarios makes students think about how a plant problem may relate to management and the environment in which it exists. Embedding DIAGNOSIS in a course Versions 1 and 2 of DIAGNOSIS were designed to be firmly embedded in a series of lectures on the diagnostic process. The software is designed to complement, not replace, hands-on laboratory work. The present version of the software does not provide reference material to assist in the diagnosis. Students are expected to use reference material from elsewhere (books, their lecture notes, the web etc.). However, version 3, presently being worked on (described below), will allow the embedding of reference material or links to it. Some History: The Genesis and Evolution of DIAGNOSIS The original DIAGNOSIS was written in 1989 in Pascal. It was designed to be used under MS-DOS. The software could show images and used a simple verb-noun combination for interaction. Readers can download this old version for free here. The relationship between this and early text-based adventure games is obvious. The builder program was simply a compiler, which parsed a formatted scenario text file and converted this to a data file for use in the student player.
Version 3.0 (almost complete) is a radical re-write, utilizing modern Windows technology and 98/NT/2000 conventions. The product will be called DIAGNOSIS FOR CROP PROBLEMS. It considerably enhances the DIAGNOSIS experience by allowing customisable menus and interfaces (Figs 4 and 5). It also allows tutors to embed (or link to) reference information. This feature enables teachers to provide not only the problem, but also information on the significance of what the student is considering at the time.
Figure 4. The Customisable Version 3 Player showing the introduction to a scenario
Figure 5. Builder Screen Shot from Version 3. With the previous version of DIAGNOSIS, students were not aware of the significance of observations until the de-briefing at the end. Here, there is the option to provide feedback as they explore the scenario. Version 3 should be available towards the end of 2001. There are a number of issues and difficulties with maintaining and supporting teaching software within an academic framework. The production and support of educational software for a specific narrow discipline is becoming increasingly difficult as operating systems become more complex, institutions become more commercially-minded and programmers become more expensive. A related symposium paper explores these problems. Final Comment Teaching programs such as DIAGNOSIS enhance student learning. However, like all technology, it is how it is used that matters. The value of DIAGNOSIS as an educational experience is not the builder and the player software, useful though these are. In fact a "Diagnosis" exercise could be done using sealed envelopes, containing photos and descriptions of facets of the scenario. When a students wants to "examine the leaves" they could break into the envelope containing observations from this activity. Lo-Tech for sure, but it would provide a similar learning experience. The real value of DIAGNOSIS is in the quality of the scenarios and how the exercises are used within a course. This quality and appropriateness of use comes from dedicated plant pathology teachers and practitioners themselves. The experience, wisdom and knowledge of extension plant pathologists can be embodied in a scenario, and used by a skilful teacher to challenge students. Technology can help but it is an aid to, not a substitute for, careful curriculum planning, inspired examples and good teaching paradigms. DIAGNOSIS is a useful tool, but it will always require good teachers to realise its full potential. References Grogan R.G., 1981. The Science and Art of Pest and Disease Diagnosis. Annual Review of Phytopathology 19: 333-351 Stewart T.M., 1992. Diagnosis. A Microcomputer-based teaching-aid: Plant Disease 76: (6): 644-647 Stewart T.M., Blackshaw B.P., Duncan S., Dale M.L., Zalucki M.P. and Norton G.A., 1995. Diagnosis: a novel, multimedia, computer-based approach to training crop protection practitioners. Crop Protection 14: (3): 241-246. Stewart T.M., 1997.
Computer games and other tricks to train plant pathologists.
In. Information Technology,
Plant Pathology and Biodiversity (Bridge, P.D., Jeffries, P. and
Morse, D.R. (eds)). CAB
INTERNATIONAL, UK End
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The
plant pathology-teaching tool DIAGNOSIS has been used at Massey
University and other institutions for a decade. This paper
describes the value in the teaching approach it uses and
it's evolution over the last 10 years. More information on DIAGNOSIS can be found
at 
