The projected visual aids are of the following types:
(а) The Opaque Projector,
(b) Teaching Slides.
(c) Film Strips.
(a) The Opaque Projector.
The opaque projector is a wonderful teaching device with the help of which it is possible to make vivid enlarged projections of objects from the size of a postage stamp of practically that of a quarto page. In an ordinary class-room, the projections can be made visible to anyone, even to a student sitting in the remote corner or on the rearmost bench.
The opaque projector will project and simultaneously enlarge directly from the originals, all kinds of written, printed or pictorial matter, in any sequence desired by the teacher.
The Opaque Projection in Teaching
The opaque projector serves many educational purposes. In procedures, the teacher may use it for the following purposes, according to his needs and teaching situations:
(i) Charts, diagrams and graphs can be projected on large screen for normal instruction.
(ii)Picture stories from any source are projected and used as an approach to reading. s
(iii) Original drawings are projected to the screen, to the delight of the young artists responsible for them.
(iv) Written composition-stories, poems, essays, letters-may be projected. This is an effective system of sharing a student's doubt. Darkness in the room focuses attention.
(v) The fundamentals of arithmetic, handwriting, spelling and composition are illustrated by use of the opaque projector.
(vi) Written or types outlines of new units of study may be projected.
It's Advantages. Haas and Packer have pointed out that with the help of an opaque projector the teacher can (i) stimulate attention, (ii) arouse interest, (iii) clarify information, and (iv) help students retain knowledge for a longer period of time.
They have further pointed out that it can also be used to-(1) introduce subject or topics. (2) Present specific information. (3) Test knowledge and ability. (4) Review instructional problems, and (5) facilities cooperative students-teacher participation in problem solving.
The Teaching Slide
Teaching slides, glass slides or projection I slides or lantern slides carry immense value in teaching procedures. The use of single side can vitalize entire teaching session. This is a successful teaching device which helps in the retention of the material taught in the minds of the pupils. A few carefully selected slides or even one pertinent slide can :
(i) Attract attention,
(ii) Arouse interest,
(iii) Assist lesson development,
(iv) Test student understanding.
(v) Review instruction, and
(vi) Facilitate student-teacher participation.
A glass side is made up of a piece of sensitized glass similar to the sensitized paper for use in photography. The slide may be in colour or in black and white. Different forms of glass slides- photographer etched-glass, slide, ink slides, etc.-may be used for teaching purposes.
Using Slide in Teaching
As pointed out earlier, slides and side-projectors are useful teaching devices which offer huge mass of usual material. Right from the lower-primary to the high school and even at the post-school level, slides serve useful teaching purpose.
Even at the programme of adult education,- slides can be usefully exhibition and instruction imparted. Some 'of the important instructional areas in which sets of slides are available and can be used are:
(5) Social Studies,
(6) Music, and
Though it is possible to have slide projectors on reasonable price in the market, yet every school cannot afford to have as slide projector. A magic lantern is a convenient device to replace the slide projector. It is not very costly. It can be conveniently improvised for class-room use.
(c) The Film Strip. The teaching film strip or the discussion film strip, "is a continuous strip of film consisting of individual frames or pictures arranged in sequence, usually with explanatory titles.
Each strip contains from twenty-five to one hundred or more pictures with suitable copy." A film strip is also a transparent projection, but differs from slides in that it is a fixed sequence of related stills on a roll of 35 m.m. film. The film strip has a number of advantages, among which may be mentioned the following:
(i) It is an economical visual material.
(ii) It is easy to make and convenient to handle and carry.
(iii) It takes up little space and can be easily stored.
(iv) It provides a logical sequence to the teaching procedure and the individual picture on the strip can be kept before the students for a length of time.
(v) It is a available both in colour and black and white.
The film strip can be projected on the screen or wall or paper- screen or the back side of a map etc. as the convenience and the teaching situation demands. A large number of subjects come within the range of film strip.
The teacher only needs to tap the right source and the right type of strip for his teaching purpose. History, Civics, Geography, Science, Mathematics, Current Affairs are some of the subjects which have been adapted to film strips. A number of film strips are available with the Central Film Library, Government of India, and New Delhi.
The following suggestions should be kept in mind while using film strip as a device:
1. For presenting film strips in the class-room, follow the procedure outlined for teaching slides.
2. Determine the lesson that could be effectively illustrated with a strip.
3. Use instructional materials that are well-selected and interesting.
. The film-strips selected should serve for the specific lesson.
4. Never miss opportunities for using the film-strip in a variety of curricular areas such as Science, History, Geography, Spelling, Reading, Art, and Music etc.
5. Pre-view film strips before using them.
6. Show again any part of film strip needing more specific study.
7. Use film strip to stimulate emotions, build attitudes, and to point up problems.
8. Use a pointer to direct attention, to specific details on the screen.
Man, woman, child, mother, hands, legs, chair, table, training, leaning, lying waling, erect, practising, sitting, posture, walk, run, stomach.
We can see men and women in different postures.
What is this man doing?
What is this woman doing?
(Point out the various postures and repeat this question.)
The child is learning to walk. Isn't he?
The woman is sitting comfortably. Isn't she?
The woman is sitting on the chair.
She is leaning on a table.
She is getting ready to run.
She is helping the child to walk.
He is standing erect.
These men are not standing erect.