Posted December 1996
This process is not so simple. First, teachers have to encode their thoughts into words and/or other forms of communication. Then students have to decode the message; this means they have to make sense of it. Of course, teachers assume and take steps to assure that what they send is received and decoded by their students in the right way. The clearer the message, the less chance there is of it becoming distorted during the transmission and the easier it is to be decoded by students. To make sure that this actually happens, teachers can do two things: strengthen their verbal messages by additional means such as visual teaching aids, thus enabling students to receive the message over two or more parallel communication lines (the ear and the eye). However, the two parallel messages must be matched in order to have an amplifying effect. If they are not, they create confusion ("noise", in the language of communication).
Agricultural teachers have an advantage when teaching in the field. Students can observe by themselves and through different channels of perception a situation which the teacher might find difficult to put (encode) into words. On the other hand, being in the field, students are exposed to many more messages (impressions) coming from the environment which can distract them. Therefore, teaching in the field must be as task-oriented as teaching in the classroom.
To make sure that students receive and decode their messages, teachers should look for feedback ­p; a sign that students have understood the message and integrated it into their conceptual framework. This feedback can be in different forms, for example verbal, when students answer questions. Feedback is often encoded in non-verbal signs, for example when students express in body language their reaction to what they have decoded from the message: they nod with their heads, they laugh after a joke, they look bored and so on. Messages that are received by the students are filtered and stored temporarly in the short-term memory. They are forgotten after about 30 seconds if they cannot be kept in mind or transferred to the long-term memory. Thus, we forget casual telephone numbers very quickly unless we make an intellectual effort to remember them. The long-term memory receives new information better when it fits into a framework of concepts which already exists. Incomprehensible and unclear messages are not easily stored in the long-term memory and they are quickly forgotten. Competing verbal and audiovisual messages are difficult to cope with. Showing something to students and talking about something different, weakens the transmission of the message. Even a blackboard left over with notes from a different subject can distract students' attention and weaken their reception of the teacher's new message.
Students' motivation can be intrinsic or extrinsic. In the first case, students are motivated from within themselves. They want to learn the subject or topic taught. They might do so for different reasons. Some students might be driven by intellectual curiosity. The teacher can keep their motivation high by giving them tasks which enable them to discover the answer to open questions and queries by themselves (e.g. from books or by observation). Such students are attracted by challenges such as project work.
Often, the specific topic taught arouses the interest and motivation of students. Especially when learning agriculture, students may already have had to tackle a similar problem and therefore see the topic's direct relevance to "real life". These students' motivation is reinforced when they feel that the topic taught is worth learning for its practical value.
Psychology teaches us, that the need of achievement is a powerful motivating factor in many individuals. Therefore, it is good practice to present such students with tasks at a level at which they can tackle them if they make an effort. Thus, they will feel they have achieved what was expected of them.
Two other types of motivation are closely related to the need of achievement: competence motivation and the novelty of the task. Some students seek satisfaction in achieving competence and mastery in a certain field, especially when this gives them a certain control or enhanced influence over their environment. They are often attracted by the novelty of a task, which puts them in a new, unfamiliar or changed situation.
Students with a high need of achievement respond well to a grading system which gives them a high ranking. However, such a system can have very negative effects on pupils with a low need of achievement or with a low self-image.
Learning psychologists have found that insofar as individuals are permitted to engage in the planning and execution of activities, they become highly motivated. However, this is only possible when students are allowed to say what they think and to criticize suggestions made by the teacher. Such behaviour might be contrary to a school's norm . Where it is acceptable, teachers can use the motive of autonomy to arouse high motivation by arranging situations that involve participation. The motive for autonomy and participation is powerful also for another reason. It is closely related to a variety of other motives, such as a need of recognition of achievement, status seeking, a need of change, curiosity and competence.
However, it is not only the topics of instruction and the tasks put before different students that reinforce (or diminish) their motivation, depending on their personality traits. The motive for much human learning resides in the interpersonal relationship between teacher and student. This view is based on the finding of many psychologists that acceptance and approval are strong personal needs in most people. Many students tend to respond to the teacher who conveys interest in them as individuals and is ready to listen carefully to them and to respect them as individuals. This is especially important, where students' motivation is based more on the need of affiliation than on intellectual curiosity and task-orientation.
It is not only the teacher who reinforces or suppresses motivation; interpersonal relationships among students have similar effects. If the classroom is organized to facilitate interaction among friends and work carried out in congenial groups, students tend to be energized and motivated. In a well-functioning group, weaker students learn from their more able peers without hampering the latter. Also, affective goals are often better achieved in a group learning situation where socialization occurs without the repression of personal traits. At the agricultural school level, the sex drive too can play a motivational role in co-educational classes. The wish to attract favourable attention by members of the opposite sex can reinforce students' motivation to excel. However, the teacher will also be alert to the negative effects which competitive behaviour can also produce.
Praise and reproof as incentives can be cues for both achievement and affiliation motivation. However, praise is the more effective, especially because reproof is felt by some students as rejection.
When intrinsic motivation is missing, students can still do well in their studies if they are motivated extrinsically, for example by their will to receive a certificate for its "market value" rather than for the competencies it certifies. Students in this category respond to teachers' comments on their chances of obtaining the desired document. Of course, also negative factors such as the fear of punishment or social disapproval can affect motivation.
It is important for teachers to know their students' expectations. These might be unrealistic and, in such a case, it is better to clarify what students can and cannot expect than to let illusions develop. Individual students are motivated by different needs and react positively to different motivating techniques. Therefore, it is not easy for teachers to reinforce the motivation of all their students at the optimal level. The most important prerequisite for teachers' success in their important task is to know their students, including their personality traits and expectations. Therefore, it is in many cases better for teachers to teach several courses to a given class, and thus become better acquainted with their students, than to concentrate on a specialized subject. This is often better than meeting a class only a few hours per week and then rushing to another class.
Among the different teaching approaches, guided discovery or inquiry teaching has an especially high motivational quality. On the other hand, it is a more time-consuming technique.
Piaget (1969) and many researchers after him have studied the intellectual development of children as they progress from one developmental stage to another. At the critical age of adolescence, students move from the concrete-operational to the formal-operational stage. At the concrete-operational stage, students develop an internalized, conceptual structure for the things they encounter, but they are not yet able to deal with possibilities not directly before them or not already experienced. They cannot go systematically beyond the information given to them. When students pass into the formal-operational stage, they are able to operate on hypothetical propositions. They are no longer constrained to what they experienced or what is before them. They can now think of possible variables and even potential relationships which can later be verified by experiment or observation. At this stage, students can express their thoughts in abstract terms without needing to refer to concrete events.
Several factors influence the intellectual development of individuals. Genetic as well as environmental factors influence the transition from the concrete to the formal stage. Teachers can help students to pass progressively from concrete thinking to the utilization of more conceptually adequate modes of thought. The problem for practising teachers lies in the difficulty of knowing where each of their students is in this developmental process. There are no ready tests available for that purpose. Based on their age, students in agricultural schools should be at the formal-operational stage, but the teacher cannot assume this to be true for all students. Actually, many adults never reach the full level of formal thinking. However, the teacher can use several techniques to be effective also with students at a lower level of concrete thinking.
One of the advantages of teaching agriculture is that it deals mainly with concrete, real life situations. When we want to come to generalizations (the value of which is discussed later), we must work at a higher level of formal thinking. Yet we can bring students who are only at the threshold of formal thinking to grasp generalizations at an "instrumental" level, as illustrated by the following example.
A group of students carried out a controlled experiment to find out how plastic tunnels affect the rate of growth of vegetables. When asked at the end of the experiment why they had used a control plot, students at the formal stage of their intellectual development answered with a more or less correct definition of a control as it would appear in a dictionary, i.e. "control is the part in an experiment in which the procedure or agent under investigation is omitted, and which is used as a standard of comparison for judging the experimental effect". What a lot of abstract terms and concepts there are in this sentence! Students who were still at a rather concrete level of operation avoided the formal definition (which they might have been asked to learn by heart, but obviously did not digest). Referring to the concrete experiment they had conducted, they said that they "had left one plot of vegetables without plastic tunnels on purpose so that they could compare these vegetables with those growing under plastic", but added that they "made sure that all the other things they did in the two plots were exactly the same, otherwise they would not know what had caused the difference". The test for this working understanding came when these students were asked to plan an experiment to find out how a change of day length would affect the time of flowering of chrysanthemums. They were perfectly able to propose the right control.
This example also shows the use of the black box approach, which is useful when we want to teach how to use an agricultural technology before students are able to understand the scientific basis on which the technology is based. Actually, we use all the time "black boxes". The television set is one of them. Who knows what is really going on inside this box? Yet we know which buttons to push. In the first experiment described above, the teacher did not discuss the different physical factors which might have caused the quicker development of vegetables under plastic (giving a higher temperature and CO2 concentration in the early morning, less wind and possibly additional factors). In the next experiment, the teacher could not explain the effect of infra-red light and the role of phytochrome in the flowering induction process. Had the students had a better background in biochemistry and physiology, the teacher could have given a more complete explanation of what happens in the plant. But for practical purposes, the level at which the lesson was taught was sufficient.
These cases show that we can teach the same topic at different levels in "an intellectually honest form", as Bruner (1960) argued. However, we have to be careful not to create misconceptions which are difficult to correct later. Many students have difficulties in understanding the law of energy conservation after they have been taught erroneously about chemical processes in which "energy is lost". The optimal solution is that of a spiral curriculum in which major topics are treated at different stages in the curriculum, but each time additional information is supplied according to the prerequisite scientific knowledge which students have acquired in the meantime and which is needed to understand the new and more abstract information. Thus, the older information is reinforced and serves as an "advance organizer".
Part of the problem of "when to teach what" is the wrong interpretation
of Auguste Comte's hierarchy of disciplines. The French natural philosopher
ordered the disciplines of the sciences according to a hierarchy in which
the findings of each discipline can be described in terms of the discipline
at a more basic level. At the base is mathematics, as a kind of natural
logic, in terms of which the findings of physics can be described and put
into mathematical form. Findings in chemistry can then be reduced to physical
principles; the characteristics of biological organisms can be seen as complex
physico-chemical systems; psychological characteristics can be expressed
in biological terms; and even sociological phenomena can be conceptualized
as aggregates of psychological systems.
One could also add agriculture at the top of the pyramid. Universities tend to base their curricula for agricultural studies on this hierarchy, demanding that students first master mathematics to be able to understand the physics and chemistry courses which, in turn, are considered a preparation for the understanding of physiology. The subject students have chosen to learn (agriculture) is postponed for a long time, thus letting students' intrinsic motivation down. In an agricultural school, the teaching of agriculture cannot be postponed until students have mastered biology and, before that, chemistry, physics and mathematics. Therefore, agricultural teachers must do two things:
Advance organizers can be used by teachers in different ways. The more clearly a teaching episode is constructed, the easier it is for teachers to present students with what they are about to teach and how it relates to previous learning. When students are asked to learn from written sources such as professional publications, they should be instructed to pay special attention to the introduction and summary in papers and to headings used in chapters or an essay, instead of going directly to the material itself. Experienced readers and researchers do the same. Abstracts at the beginning of a chapter or paper can serve as good advance organizers and facilitate an understanding of the main part of a paper.
Educational research has yielded some generalizations which can help the teacher to enhance the chances for a transfer of learning to occur. However, teachers should not automatically rely on its occurence in a specific case. Many factors influence the degree to which learning is transferred. The most important is described in the following paragraphs. The reader will observe that some psychological and instructional principles which have been found to be useful in earlier sections will reappear in the context of transfer of learning. Not all students have the same capability to transfer learning from one area to another. Age, mental ability, attitude towards learning and acceptance of the method of instruction have been found to influence the transfer of learning. Older and intellectually brighter students transfer their learning more readily than their younger and less intelligent peers. Especially important for teaching agriculture is the fact that when students regard what they have learned as being useful beyond the classroom, the transfer of learning is enhanced. This is another reason to integrate practical examples in the teaching of agricultural principles.
The transfer of learning is also improved when students learn broad concepts and principles which are applicable in different situations, and not just facts. Good teachers give their students examples from different possible areas of application when they explain important generalizations. This is especially useful when basic principles of biology are discussed. Thus, the curve of diminishing growth (which is also the curve of diminishing economic returns) can be taught with a number of useful applications, for example the optimal amounts of chemical fertilizer to be spread, of irrigation water to be supplied or of concentrates to be fed. The greater the number of similarities the student perceives between the original learning and other situations in life, the more the original learning can improve performance in other situations.
A transfer of learning is more likely to occur when the two situations are similar and when the new situation occurs shortly after the knowledge to be transferred was learned. Also, directions given by the teacher can enhance students' chances of being able to transfer learning effectively. Teachers can provide students with a diversity of problems in which they practise the application of newly learned skills and principles to varied life situations, for example situations which typically occur on farms. These problems can be at different levels of similarities:
Concepts and generalizations which the learner derives from investing personal efforts (gathering data from different sources, drawing conclusions) transfer better than those which the student was taught in form of verbal definitions. When students have to find a solution to a problem by themselves or with only partial guidance, the transfer of learning can be expected to be better than when students learn passively by listening to a lecture or even observing a demonstration by the teacher.
The transfer of technical skills seems to be more restricted. In most cases it was found that, with practice, the speed and quality of a given technical task can be improved but that this does not help to improve other practices. However, the transfer of practical training can be enhanced to some extent when students understand the principles which underlie the practices. In agriculture, this means that we can enhance the teaching of practices when we make sure that students understand why they should do things the way they are taught. For instance, a student who has understood that in cleft grafting the most important thing is to bring the cambium of scion and stock into close contact, and has got used to do this, will adapt to the parallel procedure in whip grafting more quickly than a student who has not received training in a previous type of grafting and who does not understand why the two tissues should be closely joined together.
What changes quickly are detailed pieces of knowledge. Basic rules, principles and generalizations in all the sciences change much less. In the late 1950s, a group of biologists listed the most important principles of their discipline, and this list has not changed since. Furthermore, in a study done on students' retention of learning (Tyler, 1933) it was shown that, within a year, students had forgotten 77 percent of the specific facts they had learned (the names of animal structures in a diagram). At the same time, the students' ability to apply a principle to a new situation was unchanged and the skill to interpret new experiments even improved by 25 percent, probably owing to the additional experience gained in using this intellectual skill. How, then, can we cope with the quick loss of specific facts from our memory (when they are not used after learning)? Probably the best answer is to concentrate on the teaching of principles and to use specific facts mainly to demonstrate how the principles work. Of course, specific facts can be most important ­p; once we need them. However, instead of letting students learn these specifics by rote (which is not inducive to long-term retention), it would be better to teach students how to find the details, if and when they need them. Thus, practise in the use of dictionaries, technical handbooks, agricultural compendiums and extension publications becomes an important educational goal.
Remedying the loss of details in our memory has something in common with solving the problem of "knowledge inflation". In both cases, it is important to know where to find the most updated information in a suitable form.
Furthermore, it is imperative that students learn how to learn by themselves ­p; because they will have to do this for the rest of their working life if they do not want to fall behind younger and more up-to-date colleagues. Life-long learning is not only a skill. It is also an attitude and habit which is acquired over time, mainly by exercise, and which should begin in school.
Real life problems can be quite complex, because many factors have to be taken in account and the problem might be very different from what the problem solver has experienced before that. Research has shown that two aspects define the difficulty of applying principles, rules or generalizations to the solution of a problem:
When devising application exercises, the teacher might start with a situation which is close to the one the student has just learned. In a soil science course, the problem situation would also be in soil science. For instance, after students have learned about the affinity of cations to negatively charged clay particles, they can be asked how this principle will effect various ionized nutrients in the soil. The next step could be to pose the question of how different chemical fertilizers will behave in a clay soil. In this case, students have to consider not only the chemical composition of the fertilizers but also their degree of ionization (which they might have to find in a source book or separate list provided by the teacher). The harder task will come later, when students might be requested to develop an annual fertilization plan, where the issue of fixation is just one of many principles to be considered.
Graduates of agricultural schools will often work in different parts of their country. After they have studied a farm problem on the school site and have come to a conclusion, they can then be challenged to propose a solution to the same problem, but assuming that it arises under different agro-ecological conditions (which would either be supplied by the teacher, or found by the students in relevant written sources).
In a test on students' ability to apply the rules of agricultural experimentation (Blum, 1989), students were asked three sets of questions. In the first set of questions, they had to draw a conclusion from the results of an experiment. To answer correctly, only one rule had to be applied, namely that results of an experiment are valid only for the population represented by the sample. In the second set of questions, students had to validate the correctness of an experimental design. To do this correctly, they had to apply mainly three experimental principles they had learned: controls, repetitions and randomized samples. In the last set of questions, students had to solve an agricultural problem by applying the correct biological principle chosen from an unlimited number of principles, of which they had learned quite a number.
The results showed clearly that these three sets of questions were at different levels of difficulty owing to their growing number of principles involved and their larger complexity. Especially in the last set, in which biological principles had to be applied to the solution of an agricultural problem, there was a clear difference in students' ability to solve questions relating to a familiar situation and questions describing a different, new situation.
Consequently, it is difficult to approach decision making in a systematic way. Yet, the educational literature is full of statements on the paramount importance of already teaching in school, and especially at a vocational level, how to improve decision making. When directors of applied science curriculum projects were asked what they thought about the need to introduce decision making into school curricula, nearly all gave a positive answer. However, when further questioned as to whether they had developed an appropriate decision-making exercise or planned to do so, only a few could answer in the affirmative. Here, agricultural schools and colleges with a training farm attached have a clear advantage. For a realistic learning in how to make decisions, certain conditions have to be met:
Experiential learning is not only based on school knowledge and acquired skills, but also on experience; hence its name. Experiential learning exists among many people who have never gone to school but who have grasped what is going on around them and creatively taken action to adapt to constantly changing situations. Experiential learning is a combination of "finding out" and "taking action". The process involves feelings, attitudes and values which markedly affect the disposition of the learner. These factors are to be found in any decision-making situation, although their importance is not always acknowledged. The idea of experiential learning is close to Freire's concept of "empowerment of the learner in action" (Freire, 1972).
Experiential learners should develop four basic steps:
Bawden, R.J. 1992. Systems approaches to agricultural development: the Hawkesbury experience. "Agric. Syst". 40: 153-176.
Bligh, D. 1986. "Teach thinking by discussion". Guilford, UK, Society for Research into Higher Education.
Bloom, B.S., ed. 1956. "Taxonomy of educational objectives. Handbook I: cognitive domain". New York, McKay.
Blum, A. 1989. Facet theory used to establish taxanomic subclasses for "application", with an example from science teaching. "Sci. Educ", 73: 1-12.
Bruner, J.S. 1960. "The process of education". New York, Vintage Books.
Child, D. 1981. "Psychology and the teacher". 3rd ed. London, Holt, Rinehart and Winston.
Davis, M.D. 1985. "The art of decision making". New York, Springer.
Dreyfus, A. 1985. "Education for decision making in agriculture: scientific concepts in authentic situations". In G.B. Harrison, ed. "World trends in science and technology education", p. 172-174. Nottingham, UK, Trent Polytechnic.
Fox, M. 1993. "Psychological perspectives in education". London, Cassell.
Gagne, R.M. 1974. "Essentials of learning for instruction". Hinsdale, Ill., USA, Dryden.
Good, T.L. and Brophy, J.E. 1990. "Educational psychology ­p; a realistic approach". London, Longman.
Law, B. 1977. "Decide for yourself". Cambridge, UK, Hobsons.
Lesgold, A. and Glaser, R., eds. 1989. "Foundations for a psychology of education". Hillsdale, N.J., USA, Lawrence Erlbaum Associates.
MacMillan, P. and Powell, L. 1981. "Perception and learning. An induction course for teaching in further education and industry". Huntingdon, UK, Transart.
Novak, J.D. and Gowin, B.D. 1984. "Learning how to learn". Cambridge, UK, Cambridge University Press.
Piaget, J. and Inhelder, B. 1969. "The psychology of the child". London, Routledge and Kegan.
Pye, J. 1988. "Invisible children: who are the real losers at school?" Oxford, UK, Oxford University Press.
Sutherland, P. 1992. "Cognitive development today: Piaget and his critics". London, Chapman.
Teacher Training Section, Dronten College of Agriculture and Pedagogical Advisory Center Amsterdam. 1982. "Practical guidelines for effective teaching and learning in agricultural education and training". The Hague, Ministry of Agriculture and Fisheries.