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.
