Audio Visuals Aids used in Teaching Science
These aids involve the use of sense of hearing and seeing. They provide better impact in teaching learning process when compared to audio or visual aids individually. They provide variety to teacher and students and stimulate the students to learning in a way that the teacher at times cannot.
In short span of thirty minutes of filmed documentary the student may learn more about a lesson like history of science than he could in three hours of reading or similar hours of oral lecture. Further, the student may remember it for longer time. The audio-visual aids expand the reach of the ordinary classroom.
It exposes the student to places which are either inaccessible or too dangerous for the ordinary man to visit. Some of the audio-visual aids which can be effectively used in teaching science are:
Television is an effective and good audio-visual aid in teaching of sciences. The importance of television in the communication of information, ideas, skills and attitudes cannot be undermined. Programmes on science education are one being telecasted or relayed on the different channels through satellite television. These are not only proving interesting but also beneficial from the point of view of science education.
Television channels are competing to produce best educative programmes on health, natural phenomena, wild life, life in extreme climate, medicines, human physiology, environment, agriculture, yoga, fitness exercise, food habits etc. Besides the slotted presentation by few channels some channels like National Geographic channel and Discovery channel are dedicated to science education programmes.
With the development in satellite communication, taking advantages of these programmes is also very easy. Television has now been a necessity of every house and the access to these programmes is quite easy. One has only to be careful about the tunings and schedule of these programmes for getting advantage of this vast source of information and education.
The major educational values of Television are:
i. It can heighten the interest in the topic. This is achieved through the zoom shots, magnification and split screen as the students get a good view of whatever is being demonstrated or shown on television.
ii. Television is a great equalizer of educational opportunity.
iii. A good television programme can bring the world of reality to the classroom
iv. It gives the student access to excellence. One can see and hear the gifted artist, the great scientist in television. The science programmes on television provide rich content to students and excellent instructional practices to the classroom teachers.
v. Communication using the television can be effective because it can transmit a wide rant of audiovisual materials like films, objectives, pictures etc.
Although, the television has significant educational values but the possible limitations of television as teaching aid are:
i. It may pose administrative problems in some schools.
ii. The students do not have a personal contact with the presenter or even with a teacher.
iii. Students cannot pace their learning as the television moves ahead at a constant speed.
iv. It could lead to a class of passive students.
In order to derive maximum benefits from this audio-visual aid for the good of the pupils, emphasis will have to be placed on well-conceived instructional programmed and provision made for the teachers to understand the new technology and its relationship and role in education.
b. Educational Films of Cinema:
It is prove that motion pictures are more educative than the still pictures projected through sliders or filmstrips. This more effective way by utilizing both auditory and visual senses. The films of varying scientific interest on different themes and topics are now proving a valuable aid in teaching of sciences.
The impact and advantages of the display of these films as an educational aid. These educational aids are available on wild life, marine life, human physiology, health education etc. Films of similar type can be used to explain the mechanism and application of all the important laws and principles related with all branches of science.
The films on general interest, scientific inventions, biographies and life events of the scientists are also available for deriving useful educational advantage. Considerations of length, content and overall quality will figure in the selection of any film for teaching a particular subject or topic. The various types of films which can be used ad educational aid are:
i. Newsreel which gives details of current events.
ii. School-made films depicting the activities of the school science club, science fair etc.
iii. Documentary films which gives the details of industrial plants, machines and their operations etc.
iv. Process films, review films or films on general information.
AUDIO VISUAL AIDS
Audio visual material must be seen in their relationship to teaching as a whole and to the learning process as a whole, until the teacher understands the relationship between audio visual material and teaching learning process.
Audio visual materials are produced, distributed and used as planned components of educational programs. It helps the process of learning that is motivation, classification and stimulation. A.v. aids are multisensory materials which motivate and stimulate the individual. It makes dynamic learning experience more concrete realistic and clarity. It provides significant gains in thinking and reasoning.
Audio visual aids are sensitive tools used in teaching and as avenues for learning. These are planned educational materials that appeal to the senses of the people and quicken learning facilities for clear understanding.
1. According to Kinder S. James: Audio visual aids are any device which can be used to make the learning experience more concrete, more realistic and more dynamic.
2. According to : audio visual aids are those sensory objects or images which initiate or stimulate and reinforce learning.
3. According to Carter.v.Good: audio visual aids are those aids which help in completing the triangular process of learning that is motivation, classification and stimulation.
4. According to good’s dictionary of education: audio visual aids are any thing by means of which learning process may be encouraged or carried on through the sense of hearing or sense of sight.
5. According to Edger Dale: audio visual aids are those devices by the use of which communication of ideas between persons and groups in various teaching and training situations is helped. These are also termed as multi sensory materials.
6. According to McKean and Roberts: audio visual aids are supplementary devices by which the teacher, through the utilization of more than one sensory channel is able to clarify, establish and correlate concepts, interpretations and appreciations.
7. According to KP. Neeraja: an audio visual aid is an instructional device in which the message can be heard as well as seen.
· To supplement and enrich teachers own teaching to make teaching-learning more concrete.
· To serve an instructional role in itself.
· To create interest among the group.
· To make teaching as an effective process.
1. A.V.Aids helps in effective perceptual and conceptual learning.
2. A.V.Aids helpful in capturing and sustaining attention of students.
3. A.V.Aids arouses interest and motivates students to learn.
4. A.V.Aids is helpful in new learning.
5. A.V.Aids helps in saving energy and time of both the teacher’s and students.
6. A.V.Aids provides near realistic experience.
7. A.V.Aids can meet individual demands.
8. A.V.Aids is useful in for education of masses.
Characteristics of good teaching aids:
Teaching aids should be
Ø Meaningful and purposeful
Ø Motivates the learners
Ø Accurate in every aspect
Ø Simple and cheap
Ø Large in size
Ø Easily portable
According to intellectual level of students Sources of A.V.Aids:
Ø Educational institutions
Ø Professional organizations
Ø Non-governmental organizations
Ø Voluntary organizations(national and international)
Ø Commercial producers of educational material
Ø Commercial advertisement
Ø In nursing organizations like TNAI, INC...etc.
CLASSIFICATION OF A.V.AIDS:
Various classifications are given for Audio visual aids according to the type of projection by various authors.
I) Classification of A.V.Aids
I) Audio aids
Audio materials are those which can be heard. Ex: - radio, tape recorder, walkman, Headphones.
II) Visual aids: these are helpful to visualize the things. Ex:- graphic aids, 3d-aids, display boards, and print material.
III) Audio visual aids: these aids can be heard and seen simultaneously. Ex: - projected aids, TV, films.
) Classification of A.V.Aids
I) Simple A.V.Aids: It includes graphic aids, display boards, 3d-aids, print material...etc.
II) Sophisticated A.V.Aids: includes audio-visual aids.
PRINCIPLES TO BE FOLLOWED FOR THE EFFECTIVE USE OF A.V.AIDS:
· Audio visual materials should function as an integral part of the educational program.
· A.v. aids should be centralized, under specialized direction and leadership in educational programs.
· An advisory committee consisting of representative from all areas of curriculum should be appointed to assist in selection and coordination of a.v. materials.
· An education program should be flexible.
· A.v. material should be carefully located to eliminate duplication, easy accessibility and convenient use.
· A.v. material should be available whenever and wherever they needed for effective utilization as an integral part of curriculum.
· Budget appropriations should be made regularly for a.v. education programs.
· Periodic evaluation to be done to assess the function of, utilization and expenditure of the program.
PROJECTED A.V. AIDS:
OVER HEAD PROJECTOR:
The over head projector is the most used in all a.v. aids. It projects transparencies with brilliant screen images suitable for use in a lighted room. The teacher can write or draw diagrams on the transparency while he teaches; these are projected simultaneously on the screen by the OHP.
§ Keep the screen above the heads of the participants.
§ Keep the screen in full view of participants
§ Make sure you are not blocking any ones view when presenting.
§ Darken the room appropriately by blocking out sunshine and dimming near by.
§ Turn the screen off between slides if you are going to talk for more than two.
§ Talk to the audience, not to the screen
§ To develop concepts and sequences in a subject matter area.
§ To make marginal notes on the transparencies for the use of the teacher that can carry with out exposing them to the class.
§ To test students performances, while other classmates observe.
§ To show relationships by means of transparent overlays in contrasting color.
§ To give the illusion of motion in the transparency.
§ It permits the teacher to stand in front of the class while using the projector, thus enabling her to point out features appearing on the screen by pointing to the materials at the projector it self and at the same time, to observe the students reactions to her discussion.
§ Gains attention of the student
OVER HEAD TRANSPERENCIES:
Transparencies are popular instructional medium. They are simple to prepare and easy to prepare and easy to operate with the over head projector which is light weight.
A 10*10 inches sheet with printed, written or drawn material is placed on the platform of the projector and a large image is projected on a screen behind you.
The projector is used from near to the front of the room with the teacher standing or sitting beside, facing the student.
Guidelines for making effective transparencies:
· Have one main idea an each transparency.
· Include only related figures and diagrams.
· Use simple lettering style in writing.
· Use diagrams in proposition to its lettering.
· Keep the message clear and simple.
· Emphasize the key messages.
· Use color and lettering with discretion.
· Permits face to face interaction with the students.
· Can be used in daylight conditions.
· Can present information in systemic developmental sequences.
· Requires limited planning and can be prepared in variety of inexpensive methods.
· Easily available.
THE OPAQUE PROJECTOR
Opaque projector is the only projector on which you can project a variety of materials ex: - book pages, objects, coins, postcards, or any other similar flat material that is non-transparent.
The opaque projector will project and simultaneously enlarge, directly from the originals, printed matter, all kinds of written or pictorial matter in any sequence derived by the teacher. It requires a dark room, as projector is large and not reality movables.
· Stimulates attention and arouses interest.
· Can project a wide range of materials like stamps, coins, specimen, when one copy is available.
· Can be used for enlarging drawings, pictures and maps.
· Does not require any written or typed materials, hand-written material can be used.
· Helps students to retain knowledge for longer period.
· Review instructional problems.
· Test knowledge and ability.
· Simple operation.
· Costly equipment.
· Needs to use it with care.
A slide is a small piece of transparent material on which a single pictorial image or scene or graphic image has been photographed or reproduced otherwise.
Slides are a form of projected media that are easy to prepare. They are still pictures on positive film which you can process and mount individually yourself or send to a film laboratory. The standard size of the slides is 2 “X 2 “any 35mm camera will make satisfactory slides.
Types of slides
1. Photographic slides: 2” X 2”
3” X 4”
a) Black and white
2. Hand made slides: can be made with
a) Acetate sheet
c) Etched glass
d) Plain glass
Slides can be made from photographs and pictures by teachers and pupils taking photographs and snapshots when they go on fieldtrips for historical, geographical, literacy or scientific excursions.
The arrangement of slides in proper sequence, according to the topic discussed, is an important aspect of teaching with them.
1. Requires only filming, processing and mounting by self or laboratory.
2. Results in colorful, realistic, reproduction original subject.
3. Preparation with any 35mm camera for most uses.
4. Easy to revise and up-date.
5. Easily handled, stored and re-arranged for various uses.
6. Can be combined with tape narration or can control time for discussion.
7. May be adapted to group or individual use
Film strips are sequence of transparent still pictures with individual frames on 35mm film. A tap recorded narration can be synchronized with film strip.
Each strip contains from 12 to 18 or more pictures. It is a fixed sequence of related stills on a roll of 35mm film or 8mm film.
1. Preview filmstrips before using them and selected carefully to meet the needs of the topic to be taught.
2. Show again any part of the filmstrip needing more specific study.
3. Use filmstrip to stimulate emotions, build attitudes and to point up problems.
4. It should be introduced appropriately and its relationship to the topic of the study brought out.
5. Use a pointer to direct attention, to specific details on the screen.
Types of filmstrip:
1) Discussion filmstrip: it is continuous strip of film consisting of individual frames arranged in sequence usually with explanatory titles.
2) Sound slide film: it is similar to filmstrip but instead of explanatory titles or spoken discussion recorded explanation is audible, which is synchronized with the pictures.
1) Are compact, easily handled and always in proper sequence.
2) Can be supplemented with recordings.
3) Are inexpensive when quantity reproduction is required.
4) Are useful for group or individual study at projection rate are controlled by instructor or user.
5) Are projected with simple light weight equipment.
NON PROJECTED A.V. AIDS:
It is a combination of graphic and pictorial material designed for the orderly and logical visualizing of relationships between key facts and ideas ex: comparisons, relative amounts developments, processes, classification or organization. It includes the following
These visual symbols used for summarizing, comparing, contrasting or performing other services in explaining subject matter. A chart is a combination of pictorial, graphic, numerical or vertical material, which presents a clear summary.
Chart is defined as a visual aid which depicts pictorial and written key information in systematic way to summarize, compare, ex: anatomical charts and figure, diagrams etc.
Ø To visualize an item, it is otherwise difficult to explain only in words.
Ø To highlight important points.
Ø To provide outline for materials covered in presentation.
Ø To show continuity in process.
Ø For creating problems and stimulating thinking.
Ø For showing development of structure.
Types of charts:
Ø Narrative chart: Arrangement of facts and ideas for expressing the events in the process or development of a significant issue to its point of resolution or we can show an improvement over a period of years.
Ø The chain chart: arrangement of facts and ideas for expressing transitions or cycles.
Ø The evolution chart