Discovery

Distance Learning

by Janine Griffin

Distance education once meant the rather solitary life of a correspondence student, but new technology is giving students a chance to hear and see their far-away teachers.

Distance learning began in New Zealand in 1922, when the Correspondence School was established for primary school students living in remote areas. Since then, correspondence has become an option for primary, secondary and tertiary students, and the number of institutions offering a correspondence option has grown. Although a wide range of courses are available, the learning is still limited mainly to the printed and written word.

Learning takes place through three main avenues of communication -- speaking, reading and seeing. Some correspondence courses do make use of audio and video tapes, and many have a residential component, but teaching is mainly through print. Asking questions and getting immediate answers or seeing how something is done rather than reading about it is not possible through correspondence. Now, though, advances in communication technologies are making possible direct communication between a student and teacher distant from one another.

The Distance Teaching Unit at Otago University is one of the institutions making use of these recent advances. The unit offers a number of courses through its distance teaching audio network, called Unitel. The university began setting up this network about ten years ago and now has 45 sites throughout New Zealand.

This year, over a thousand students enrolled for distance credit courses, says Elizabeth Purdie, the senior programme officer. The courses offered range from the sciences to the humanities, and many are involve specialist areas. The Postgraduate Diploma in Obstetrics, for example, is designed for postgraduate medical students, to complement their hospital-based studies.

Sound Learning

Students receive the bulk of course material through the mail, as in traditional correspondence courses, but every week or so, tutor and students "meet" on the audio network. Otago's Unitel network is based around fixed four-wire circuits running to each of the audio conference sites, which are equipped with conference terminals, amplifier\loudspeakers and push-to-talk microphones, usually one for each participant.

Because speakers can't see each other, they give their name and location when they start speaking. This announcement is often unnecessary in smaller courses, where students become familiar with the different voices as the course progresses. In larger courses, though, this etiquette is necessary if time is to be used efficiently.

The Unitel system has better sound quality than ordinary teleconferencing through the public telephone system, and the fixed circuits eliminates the need to ring each location. It can also be linked up to the two-wire telephone system, which means courses can make use of outside lecturers, from within New Zealand or from overseas.

The audio sessions are not lectures, says Purdie, but tutorials. They provide the opportunity to discuss the course material with other students as well as with the tutor, and problems can be solved on the spot. The printed material distributed prior to sessions is the basis for discussion, and the teachers need to be well-prepared.

"You have to be really organised well ahead," she says, "because everything the students need to know has to go out to them through the mail at an early stage."

Interaction An
Advantage

In fact, many tutors have found their on-campus teaching has improved because of the habits they develop through distance teaching. The greatest advantage of the system is the opportunity for interaction, says Purdie. Many of the students are professionals and the audio sessions give them the opportunity to communicate with others working in the same field. They're able to bounce ideas off one another, which is something they might normally do only at the occasional conference.

Motivation is usually a problem with correspondence courses and drop-out rates tend to be high. Some overseas distance education courses have attrition rates of around 50%. The rate is only about 12% for Otago's distance credit courses, says Purdie, and most withdrawals occur at the start of a course. Purdie believes the interaction acts as motivation.

That interaction is one of the best things about the new technology of distance teaching, according to Cynthia Wood and Barbara Mowat-Davies. Both are taking courses in Christchurch through Otago's Distance Teaching Unit. "I wouldn't be able to do a regular university course," says Mowat-Davies, who has two children. She is studying for a Diploma in Sports Studies and is taking two papers this year. Once finished, Mowat-Davies hopes to work as a personal trainer or in a gymnasium.

The contact with other students doing the same course is the greatest advantage, she says, along with being able to ask questions and have them answered on the spot. She finds that the direct contact makes it easier to know what parts of the course material should be emphasised. Knowing what areas other students are having problems with helps as well, says Mowat-Davies.

Wood works full-time as a high school teacher and is studying for a Postgraduate Diploma in Science (Biotechnology). She has postgraduate qualifications in education, and saw the course as an opportunity to keep up with modern technology, linking her interest in biology and chemistry. She's really enjoying the course, she says, and finds the professional contacts very helpful.

The audio network is also used for teaching students overseas. The university collaborates with the University of Hong Kong in teaching Otago's Master of Pharmacy course. The course is designed for students who are practising pharmacists, and can be completed in four years of part-time study.

Educational Television and Interactive Video

The next step up the distance learning ladder is to bring the visual medium into courses. The Auckland Institute of Technology and Television New Zealand began offering television learning earlier this year. The first two courses offered were psychology and French, followed by marketing. Students have a choice of simply watching, enrolling and receiving textbooks and study guides, or registering for assessment and exams. But television learning is only one-way; there is no teacher-student interaction. Video conferencing, or interactive video, provides that interaction.

Interactive video is the teaching medium that most closely matches the actual classroom, says Ray Dickinson, a tutor in the Department of Information Technology at Waikato Polytechnic. Waikato has an interactive video link with its Thames campus and has been using the link for teaching since the beginning of this year. The link uses Integrated Services Digital Network technology which joins existing technologies into one digital network, allowing voice, image and data services to use the same line.

The Waikato-Thames link is currently being used about 20 hours a week for courses in a wide range of areas. The video link brings in body language, says Dickinson, and tutors can show their students things rather than describing them, or waiting for the material to arrive in the mail. For a horticulture course, for instance, the tutor can show the students leaves, fruits or different pruning or propagation techniques.

Audio and video links still require students to travel to a site. In the future -- perhaps the near future -- these types of learning will be available in the home through ISDN. Once the cost of this currently expensive technology falls, distance learning students will be able to communicate, using both sight and sound, with students and teachers throughout New Zealand without leaving home. And because ISDN works to an international standard, they could become students of the world.

Janine Griffin is a journalist specialising in science issues.

What I want to know is ...

why does fresh pineapple irritate the throat?

Because you haven't peeled it properly. The idioblast cells close to the skin of the pineapple contain clusters of tiny needle-shaped calcium oxalate crystals known as raphides. When ripe, the cell walls are fragile and break easily, releasing the sharp crystals to irritate the mouth and throat. Pineapple juice, which is often made from pineapple peel, can have a large number of these raphides floating around in it.

Kiwifruit is the only other commercially important fruit to have this crystal formation, but it only becomes a problem under special circumstances, according to Dr Conrad Perera of HortResearch. Fresh kiwifruit does not irritate the throat because the sharp raphides are safely held within the mucilage inside the cell. When you eat a fresh, ripe kiwifruit, the idioblast cells move away from the line of action of the teeth and remain intact.

Pulping or dehydrating the kiwifruit releases the raphides, each spiky crystal measuring about 100 microns long and three microns wide. The idioblast cells are broken up during pulping, and the mucilage shrinks around the crystals, exposing their sharp ends. Perera and his colleagues have been examining ways of alleviating this.

Taro has even longer raphides and can also hurt the mouth and throat. Researchers believe that grooves which run down the side of the long calcium oxalate crystals hold a toxin, which aggravates the irritation. Fortunately, there are only a very small number of idioblast cells, and most of them are near the sprout end of the tuber, says Perera.

Janine Griffin is a freelance journalist specialising in science issues.