DEMONSTRATION METHOD

DEMONSTRATION METHOD

This method includes the advantages of both lecture and demonstration method and avoids the disadvantages of both the methods. The main demerit of the lecture is that it is a one-side process. The teacher talks too much and the students are neglected. The best method is that which involves a kind of interaction between the teacher and the taught because they are really part of an educative process. The teacher performs experiments before the class and meanwhile goes on asking relevant questions. The students are compelled to observe carefully because they have to describe each and every step of the experiment accurately and draw inferences. The students are questioned and cross questioned concerning the problem in hand and their inferences are discussed in the class. Thus unlike in a lecture, the students are active participants in a demonstration and their faculties of observation and reasoning are properly exercised. The students see the actual apparatus and operations and help the teacher in demonstrating the experiment and thereby they feel interesting in learning. It is difficult to talk about the thing, which the students have to imagine. It is always easy for the students to understand and remember the concrete things. This method is said to be in accordance with the maxim of teaching “from concrete to abstract”.

The lecture-demonstration method can prove to be one of the best methods if the demonstrations are, well planned and rehearsed by the teacher. If the demonstration fails, it creates a very undesirable effect upon the moral and attitude of the students. If failure is too frequent, confidence of students in the teacher is lost. And if the demonstration is successful it will form a desirable effect on the students and will help in achieving the objectives of teaching of biology.

Criteria of a Good Demonstration

There are several criteria, which are more important for this method. If they are kept in a view by the teacher the demonstration will be a successful one. The following are the criteria of good demonstration.

• The demonstration should be planned and rehearsed well in advance. Planning and rehearsing of the experiment is very essential for it gives confidence to the teacher. He finds the difficulties involved in the experiments and the precautions to be observed. The students will be discouraged because of the badly planned lessons. If the experiment fails the students may lose interest and confidence in the teacher and in the lesson. In some instances a well – rehearsed experiment may also fail in the class. At such occasions the teacher should turn it into a problem for the students. In this way, the interest and confidence of students will not be lost but on the other hand they will feel more interested in finding out the cause and then presenting it before the class. This will encourage the students to exercise the powers of observation and reasoning and at the same time their instinct of self-expression will also be satisfied.

• The teacher should be clear of the purpose of demonstration. He should be very clear about the objectives of the demonstration, the comparisons to be made the generalization to be arrived at, applications to be made and the attitudes to be developed.

• The teacher should get the help of students in arranging, filling up and performing the experiment. It should be the participation of both the students and teacher.

• The teacher should ask questions in order to know that the students have understood and are attentive in observing the demonstration.

• The teacher should explain the important and difficult points involved in the demonstration in simple and comprehensive language and should write them on the blackboard.

• The apparatus for demonstration should be arranged in order. It is always better to keep the apparatus to be used on the right hand and the used one on the left hand side.

• The demonstration should be visible to all the students in the class.

• The demonstration should be at a little higher level than the student’s table.

• Proper care should be taken for adequate lightning and to size the clarity of the apparatus.

• Demonstration experiments should be simple and speedy. Lengthy demonstrations in which the students have to wait for long time destroy the interest of the students. At the same time the complicated apparatus, which is above the understanding of average students, also discourages them. So the experiment should be simple and move on quickly to the conclusion.

• Demonstration should fix in the sequence of experiment, which the students carry out themselves and should be consciously connected with the things seen and handled by the students.

• Demonstration should be in accordance with the time and season otherwise it will prove to be

a failure.

• Demonstration should be supplemented with other teaching aids to make it more real and interesting.

• Demonstration should create problems for the students and also make provision for solving them through their own efforts. In this way the students will find a chance to exercise their own abilities to observe, explain, analyze, verify and review. They will get training in scientific method of solving problems.

• The teacher should maintain the interest of the students throughout the experiment.

Principle

This method is based on the principle: Truth is that which works. The teacher has to work out something and then only the students will believe.

Requisites for a Good Demonstration

The method, though very popular and most widely used, may not prove successful with some teachers. The following are some of the requirements which will assure that the demonstration will be a success.

• Appropriate Arrangements: while performing an experiment the teacher must be sure that everything done on the demonstration table is clearly visible to the pupils. There will be no difficulty if a lecture gallery is available but in its absence there are several ways of enabling the pupils to get a better view.

• When there is no demonstration table: The teacher may carry on the experiments on one of the student’s table located in the front row and the class can view the demonstration by standing at some distance round the table. This method may prove very useful with small classes.

• Sufficient Light: Attention must be paid to adequate lighting of the demonstration table and the back-ground. Additional illumination may be used if necessary. Proper back-ground is very important. Black things should never be shown in front of the black-board.

• Demonstration Apparatus: Demonstration apparatus should be large as possible such as a big model of electric bell, vernier calipers etc. and the graduations on any instrument should be clearly visible.

• Arrangement of Apparatus: everything must be placed in order before the demonstration starts. The apparatus to be used should be placed on the left hand side of the table and arranged in order in which it will be shown. After a particular thing or apparatus has been used, it should be transferred to the right hand side. When several things are to be shown, they should not be placed all at once. A wealth of apparatus may impress a student but it can confuse him as well. The general order and tidiness of the demonstration table is very essential. Nothing looks worse than a demonstration table littered with books and other useless things. Only the things relevant to the lesson should be placed on the demonstration table.

• Preparation by teacher: the teacher must be sure that the experiments will succeed and are strikingly clear. This demands adequate preparation on the part of the teacher and rehearsal of the experiments under the conditions prevailing in the class-room.

• Securing attention: Attention of the class is very important. The teacher should know various methods of arresting and creating interest. He may, at occasions, be a bit of a ‘showman’. To inspire the class with a sense of dramatization and to arouse an atmosphere of suspense just before the critical point of an experiment, is an art. It is useful to a teacher as to an actor.

• Effect of Season: Proper account should be taken of time and season. Climate conditions sometimes affect the apparatus. For instance, frictional electricity experiments should not be done during rainy season. Hot season is best for experiments with ice. White phosphorus can be safely used on a cool day.

• Teaching Aids: Demonstration experiments should be supplemented with teaching aids like charts, pictures, diagrams, models, film strips etc.

• Use of Black board: A large black-board behind the teacher’s demonstration table is most essential. During the lesson the teacher can use it to great advantage. Tabular statements for entering data, principals arrived at, as a result of demonstration, can be written on the blackboard. Necessary simple diagrams can be drawn on it.

Conduct of a Demonstration Lesson

Lecture demonstration method is the most suitable method to teach biology. It, therefore, seems appropriate tom discuss some of the essential steps to be followed in a demonstration lesson.

1. Planning and Preparation

The adoption of demonstration method requires a thorough preparation on the part of the teacher. While preparing, he must bear in mind the following points:

a. Subject matter

b. Lesson plan including the questions to be asked.

c. Collection and arrangement of apparatus required.

d. Rehearsal of experiments.

The teacher should study the lesson before he enters the classroom. This will enable him to be exact and to the point. Drawing up a lesson plan is equally necessary and this should include a list of the principles to be explained, a list of the experiments to be demonstrated and the type of questions to be put to the students. This will make his work very systematic. Each and every experiment should be rehearsed under the same conditions hat prevail at the time of demonstration. Rehearsal of experiments will enable the teacher to collect all the requisites for the demonstration work. It is all the more important that each and everything is arranged on the demonstration table in a wise and proper order so that no difficulty is felt at the time of demonstration.

2. Introducing the Lesson

It is useless to start a lesson without properly motivating and preparing the minds of the students for it. The lesson should be introduced in a problematic manner so that the student can appreciate and realize the importance of topic in hand. When a teacher is able to awaken the keenness and enthusiasm of his students half the game is over. Much depends upon starting a lesson in the right way. The teacher should begin the lesson with some personal experience or mind incident, a simple and interesting experiment, a familiar anecdote or by telling a story. He should keep in mind the value of an interesting experiment the experiment, which will set his students talking in school and out of it, about the wonderful things they have seen or done in the biology lesson. The teacher should maintain the interest and enthusiasm of the students alive throughout the lesson.

3. Presentation of the Subject matter

The actual lesson may be concerning some prescribed topic, but the teacher is at liberty to treat it in narrow sense or to introduce into his teaching material and illustrations from a wide field of knowledge and experience. Even if the lesson deals with a particular topic of biology, a widely read and well informed teacher will draw illustration from all branches of science. In addition to this wherever practicable, reference should be made to the names of great scientists and their works. The lives and achievements of great men are always sources of inspiration and an acquaintance with their early difficulties encourages the students.

Teaching, as far as possible, should be through well thought out and judicious questions. The questions should be so arranged that their answers form a complete teaching unit. In the teaching of a lesson the voice of the teacher plays an important role. The teacher should speak slowly, deliberately and with correct pronunciation. The teacher should use voice effectively. It should be pleasant and not jarring. The tone his voice should be modulated according the nature of the statement.

4. Performance of experiments

The work at the demonstration table should be a model for the students to copy. The demonstration table should be clean and dry. The experiments must work and their results should be clear and striking. The experiments should be simple and speed. They should be well spaced throughout the lesson. They should be convincing and striking. Reserve apparatus should always be kept near the demonstration table so that much time is not wasted in collecting the apparatus in case of breakage. It is wise to keep the demonstration apparatus intact until it is to be used again.

5. Blackboard work

In the lecture demonstration method backboard is very useful. It mainly used for:

a. Writing important results and principles in summarized form.

b. Draw necessary sketches and diagrams.

As the face is an index to one’s mind, blackboard work is an index to a teacher’s ability. The writing on the blackboard should be neat, clean and legible. ‘’Single lined’ diagrams should be preferred to ‘double line’ diagrams. Every part of the diagram must be properly labeled. The labeling should be written in script and not in running hand.

Copying and Supervision

At the end of the demonstration the students should be given time to copy the black board summary and the sketches. A record of the blackboard summary will prove very useful for further reference.

Common Errors in a Demonstration Lesson

Some of the most common errors committed by the beginners in giving demonstration lesson are summarized below:

1. The apparatus may not be ready for use.

2. The teacher may fail to show how the demonstration fits into the problem in hand.

3. The teacher may not be able to focus the attention of the students to the important facts of the experiment.

4. Black-board may not be used properly.

5. The minor facts may be given as much importance as the major facts.

6. The teacher may arrive at the generalization himself rather than getting it done by the pupils.

7. The teacher may fail to emphasize the generalization.

8. The language used by the teacher may be difficult for the students to understand.

9. Right type of questions may not have been asked.

10. The persistent and continuous talking by the teacher may have marred the enthusiasm of the children.

11. Sufficient time for recording data may not have been given to the pupils.

12. The student’s interest for further study may have been over-looked.

Merits:

• Psychological Method: This method is psychological because the students need not imagine anything, instead they are shown concrete things and living specimens. Consequently they take active interest in teaching –learning process. It, therefore, motivates their interest and enthusiasm of science.

• Sensitive Apparatus: Demonstration is very suitable technique when the apparatus is very costly or very sensitive and is likely to be damaged if handled by the students e.g., Fortin’s barometer, electric dynamo etc.

• Useful in dangerous Experiments: It is helpful in case of dangerous experiments like preparation of chlorine, burning of hydrogen etc.

• Economical: The method is considered most economical. When apparatus is not sufficient for the students to do practical individually, the teacher may perform the experiment before the whole class. Also it saves time when a number of experiments can be performed in a short time.

• Time Saving: It is a time-saving method. If compared to Heuristic, project or Experimental methods, it saves much time. On this score it cannot be compared to lecture method, which is too fast.

• Based on Activities: Although it is not a child-centered method, yet the students are kept engaged in various activities like observing, taking notes, answering questions, drawing diagrams and sometimes involving in the actual performance of experiments.

• Useful for everyone: It is suitable method for all types of students i.e. average, below average and above-average.

Demerits

• Not Based on learning by Doing: There is no scope for ‘learning by doing’ which is an important principle of learning and the students do not realize the joys of direct personal experience.

• Not Child Centered: It is not child centered. The teacher has the final responsibility to manipulate and perform the experiments in any manner he likes. Therefore, to some extent it is an authoritarian approach, and is teacher dominated.

• No scope for Individual differences: This method does not provide food for individual differences. Slow learners and genius are made to crawl at the same pace.

• Obstacle in Progress: The desirable laboratory skills are not developed among the students.

• Not based on Scientific Attitude: It does not inculcate the most-needed scientific attitude and training in scientific method.

Conclusion

This method is one of the best methods for teaching science to secondary classes. However, if the teacher feels that it will tax upon his time and he will have to put in more work by rehearsing, arranging and then demonstrating, it is suggested that the teacher can, to much extent, call upon his pupils for help. There can also be pupil-demonstrations. Let the pupils do everything regarding arranging, rehearsing etc. No doubt the teacher will always be guiding. In this way, the objection against this method that it is devoid of ‘learning by doing’ will also be removed.