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. Burton
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.
II) 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.
· Needs a dark room for projectio
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 cause and effective chart: Arrangement of facts and ideas for expressing the relationship between rights and responsibilities or between a complex of conditions and change or conflict.
Ø The chain chart: arrangement of facts and ideas for expressing transitions or cycles.
Ø The evolution chart: facts and ideas for expressing changes in specific items from beginning data and its projections in to future.
ØStrip tease chart: it enables speaker to present the information step by
It increases the interest and imagination of the audience.
The information on the chart is covered with thin paper strips to which it has been applied either by wax, tape or sticky substance or pins.
As the speaker wishes to visually reinforce a point with words or symbols, he removes the appropriate strip or paper. It produces interest.
It increases learning and aids recall.
Ø Pull chart: it consists of written messages which are hidden by strips of thick paper. The message can be shown to the viewer, one after another by6 pulling out the concealing strips.
Ø Flow chart: diagrams used to show organizational elements or administrative or functional relationships. In this chart lines, rectangles, circles, are connected by lines showing the directional flow.
Ø Tabulation chart: it shows the schedule of an activity or of an individual ex: time-table of a class. These are very valuable aid in the teaching situation where breakdown of a fact or a statement is to be listed. Also it is a useful aid for showing points of comparison, distinction, and contrasts between two or more things. While making the table charts the following points must be kept in the mind.
The chart should be 50 X 75 cm or more in size.
The chart should be captioned in bold letters.
The vertical columns should be filled in short phrases rather than complete sentences.
Ø Flip chart: a set of charts related to specific topic have been tagged together and hang on a supporting stand. The individual charts will carry a series of related materials or messages in sequence. The silent points of specific topic will be presented.
Ø Pie chart: a circle will be drawn and divisions will be made into different sections, each section will be coded differently and code key will be given at right corner of the chart as legend. The circumference is divided into suitable sections. It is relevant for showing the component part
“Flash cards are a set of pictured paper cards of varying sizes that are flashed one by one in a logical sequence.”
‘’Flash cards can be self made or commercially prepared and are made up of chart or drawing paper, plane paper using colors or ink on them for drawings.’’
1. To teach the students.
2. To give health education.
3. Useful for small group.
4. Used in group discussions.
· The messages can be brief, simple line drawing or photographs, cartoons and the content will be written in few lines at the back of the each card.
· 10” X 12” or 22” X 28” is commonly used size.
· 10-12 cards for one talk can be used. It should not be less than 3 and more than 20.
· Prepare a picture for each idea which will give visual impact to the idea.
· The height of writing on the flash card is to be approximately 5cm for better visualization.
Using the flashcards:
For class room instruction, the flash card s is to be properly used. The following steps are used while displaying flash cards.
1. Give brief introduction about the lesson to students.
2. Give instructions to students about their actions while you flash the cards.
3. Flash the card in front of the class by holding it high with both your hands so that all the students can see it.
4. Let the student respond as per instructions already given.
5. Review the lesson by selectively using flash cards.
· Flash cards can be used to introduce and present topics.
· It can be used to apply information already gained by students to new situations
· It can be used to review a topic.
· Can be used for drill and practice in elementary classes
· To develop the cognitive abilities of recognition and recall of students.
· It can work as a useful supplementary aid and can be effectively used with other material.
· Can not be used for a large group
· Prone to get spoiled soon
· Preparation is time consuming.
“Posters are the graphic aids with short quick and typical messages with attention capturing paintings.”
· To provide general motivation.
· To create an esthetic or atmospheric effect.
· To communicate a more general idea. To thrust the message for leading to action.
· For the class room and community.
Preparation and rules:
· To do a special job.
· To promote one point.
· To support local demonstration.
· Planned for specified people
· Tell the message at single glance.
· Use bold letters.
· Use pleasing colors...
· It should place, where people pass or gather.
Features of a good poster:
· Brevity: message should be concise
· Simplicity: message should be easily understandable
· Idea: should base on single idea and it should be relevant.
· Color: suitable color and combination should be used to make the poster attractive and eye catching.
· Display: while displaying one should be sure to find a place where there is ad4equate light and where the larger population will see it.
· It attracts attention.
· It conveys the message very quickly.
· It does not require a detailed study.
· Good poster leads to action with good motivation
· It can stand alone and is self explanatory.
Poster does not always give enough information
When a poster is seen for longer time it may not attractive. So it should be dynamic
Graphs are the visual teaching aids for presenting statistical data and contrasting the trends or changes of certain attributes.
Method of preparation:
· Before making the bar chart makes a rough sketch of it in a note book.
· For drawing the bar graph use the chart paper of 50x 72 cm size.
· Use two different color shades for the two contrasting groups.
· The bars should be equi-spaced.
· Write the key to the bar graph in a box on the right hand side corner of the chart paper.
· Numbers specifying the magnitude of the bars should be on the top on the bars.
Pie graph: These are called as circle diagram. The data are presented thorough the sections of portions of a circle.
· In determining the circumference of a circle we have to take in to consideration a quantity known as pie.
· The surface area of a circle is to cover 360 degree.
· The total frequencies or value us equated to 360 degree and then the angles corresponding to component parts are calculated.
· After determining their angle, the required sectors in the circle are drawn.
The graphic presentation extends the scale horizontally along the length of bars. Each bar must be of the same width, height of the bar over a period represents the corresponding time of the variable. Graphs are available in 2 forms that is vertical and horizontal
To show the trends and relationships ex: single line shows the relation and the variation in the quantity. Quantitative data are plotted or when the data is continuous. The concepts are represented with the help of lines drawn either horizontally or vertically. The plotted points are connected to one another, instead of the base thus producing the curve.
It is an out standing method of graphic representation. Pictures are used for the expression of ideal; they are more attractive and easily understood. Vivid pictures will be used to create rapid association with the graphic message; each visual symbol may be used to indicate quantity.
A map is a graphic aid representing the proportionately as a diagram, the surface of the earth, world or parts there of. It conveys the message by lines, symbols, words and colors.
Types of maps:
v Political maps: these maps show political divisions of the world, a continent, a nation.
v Physical maps: shows the physical contour of a place, area, and region.
v Relief maps: it shows the actual elevations and depressions in a place, area, and region.
v Weather maps: shows the amount of rains, temperature extremes, humidity in an area, region country.
v Population maps: shows the distribution of population in various parts of region, country.
v Picture or tourist maps: shows historical spots monumental sites.etc..
v Road maps: shows the roads of a region connecting various parts and points together.
v Railway maps: shows the railway links between various points.
v Air maps: shows the air routes between various points.
v Sea root maps: shows the sea routes between various sea ports
CARTOONSThe word cartoon has various meanings, based on several very different forms of visual art and illustration. The term has evolved over time.
The original meaning was in fine art, and there cartoon meant a preparatory drawing for a piece of art such as a painting.
A cartoon is humorous caricature which gives a subtle message.
In a cartoon the features of objects and people are exaggerated along with generally recognized symbols.
· The quality of the drawing should be high primarily for visual effectiveness.
· The symbols used should be familiar and represent a concept or idea to which students can react intellectually.
A cartoon can be effectively used to initiate certain lesson.
· It can be used for making a lesson lively and interesting.
It can furnish health messages in local languages which cancan reach to the public easily. The information will be available in low cost, easy to read and understand simple language .the people may learn to read and interpret the contents along with pictures to enhance easy grasping.
ü Best method to reach a large group
ü Pictures will help in easy understanding
ü Attractive and easy to understand
Lot of information can be obtained in various fields
ü useful for literates only
ü detailed information cannot be produces
A comic strip is the graphic depiction in a series of pictures or sketches of some character and events full of action.
This medium of communication is found very interesting and exciting by children.
· Comic strips fire the imagination of children
· It boosts the courage of children and builds up the spirit of adventure.
· It communication detailed and vivid.
· It stimulates reality and involvement.
· Comic strips misguide children by depicting characters with supernatural powers divorced from the hard realities of life.
· Comic strips hamper the development of language of children.
· Classics brought out in the form of comics develop the tendency in children to ignore or by pas s the original work.
· Comics can soon become an obsession with young children and they tend to avoid serious studies
3- DIMENTIONAL AIDS
Definition: a model is a recognizable representation of a real thing three dimensionally, that is height, width, and depth is felt as reality.
Types of models:
1. Solid models: it is the replica of an original thing made with some suitable material like clay, plaster of Paris, wood, iron etc. to show the external parts of the things. Ex: globe, clay model of human and animal.
2. Cutaway and x-ray models: are the replicas of the original things to show internal parts of a thing. Cross sectional models are difficult to make in the class room or institutions as they require expertise to construct them. Ex: cross sectional model of human body.
3. Working models: these models are either actual working things or their miniature replicas. For illustrating an operation. Ex: a motor, a generator.
4. Sand models: made by using sand, clay, saw dust, ex: a tribal village, a forest area.
· Models heighten reality of things and make learning direct and meaningful as they are three dimensional.
· Models illustrate the application side of certain principles and laws.
· Models explain the complex and intricate operations in a simplified way and thus make comprehension easier.
· Models are lasting and ultimately work out to be cheaper teaching aids.
· Still models are easy to make with the help of discarded materials like empty boxes, pins, clips, nails, and clay.
· Models are to reasonable size and convenient to handle.
· Models involve the use of all the five senses and thus make learning effective.
· It requires expertise to make.
· Time consuming.
· Some of the models may be very expensive.
A collection of real things for instructional use refers to objects.
A specimen is a sample of the real object or a material.
Using objects and specimens: while using the specimen and objects as teaching aids, a teacher must keep the following points in her mind.
· Plan your teaching with certain simple and direct observations of the object or specimen being referred to.
· Ask questions from the students to elicit more details of the features of the object or specimen under observation.
· Clarify and emphasize important structural details of the object or specimen under observation
· Provide review and practice to make learning permanent.
Sources of objects and specimens:
· Local markets
· Manufacturers and factories
· Discarded material from the houses
· Specimen found in the nature can be collected by students from field trips and nature hunt
· Plasters casts can be purchased
· Wild flowers, leaves shells, stones butterflies moths, insects can also be procured.
Mounting the objects and specimens:
Objects and specimens should be mounted in shallow boxes in an artistic way and the boxes should be covered with cellophane paper. Also label each object or specimen using self adhesive paper.
Advantages of objects and specimens:
· Collection of objects and specimens by students requires interaction with others leading to development of social skills and values.
· Students when collect and display objects and specimens derive satisfaction of contributing to the school and teacher something worthwhile.
· Student’s power of observation and first hand experiences is enhanced by collection of objects and specimens.
· Student’s personal collection of objects and specimens can be good source of doing investigatory projects.
· Collection of objects and specimens become an interesting educational pursuit of the teacher and students alike.
· It arouse some interest among students in learning
· Objects and specimens involve all the five senses in the process of learning
· It heighten the reality in the class room
· It makes teaching lively.
Many times in the school, a department of the school or a class put up their work for showing it to the people out side the school, and such a show called exhibitions.
The pieces of work done by the students for an exhibition are called exhibits.
Requisites for exhibition:
· The exhibition should have a central theme with a few sub themes to focus attention to a particular concept
· The exhibits should be clean , labeled properly
· The concepts of contrast in color and size should be used for lying out the exhibitions
· The exhibits should be so placed so the most visitors , can see them
· The place and exhibits should be well lighted
· To capture attention and interest of visitors , both motion and sound should be utilized
· The exhibition should have some exhibits with operative mechanism such as switches, handles, to be operated by the visitors to observe some happenings.
· The exhibition should include lot of demonstrations as they involve deeply the students and the visitors
· The exhibition should be able to relate various subjects’ areas to provide integrated learning.
· Exhibitions inspire the students to learn by doing things themselves and they get a sense of involvement
· Exhibitions give students a sense of accomplishment and achievement
· Exhibitions develop social skills of communication , cooperation, coordination
· Exhibitions foster better school community relations and make community members conscious about the school
· Exhibitions couple information with pleasure
· Exhibitions foster creativity among students.
· Requires thorough preparation
· Time consuming
· Require funds or budget.
A museum is a building displaying a collection of historical relics, antiques, curiosities, works of arts, works of science, literature and other artifacts of general interest.
Museums can be useful both for public education and specific class room instructions.
Setting up school museum:
· School should have enough space
· Take the help of students, collect old and new objects and articles
· Accept donations from various organizations who donates the articles
· Students can be guided to prepare the exhibits
· All the collected and prepared articles should be displayed and labeled
· A detailed report book should be maintained giving a brief description of each museum pieces
· The museum rooms should be well lighted
· It should be cleaned and maintained timely.
A diorama is a three dimensional arrangement of related objects, models, and cut outs to illustrate a central theme or concept.
The objects and models are generally placed in a big box or show case with a glass covering and background printed with a shade or a scene. Ex: a harvest scene, a planting scene etc.
· Provide a good opportunity to learn
· It gives the appearance of actual things which can not be brought to the class room
· Interesting and enhance creativity
· Live things also can shown in diorama ex: aquarium
· Provides students to do project works
Disadvantages: sometimes cost effective
· Needs expatriation for the preparation
· Require budget
· Sometimes it may misguide the student if is not the replica of actual thing.
It emphasizes the functional relationship between the device reality and its workability. Certain element of the original reality is emphasized to make it more meaningful for the purpose of instruction.In common usage, a mockup is a scale model of a structure or device, usually used for teaching, demonstration, testing a design, etc.
Mockups are also used in the Consumer goods industry, as part of the product development process, when the size, impression and/or artworks have to be tested and approved.
Mockup is also a frequently used term when talking about an early layout or sketch of a Web site or GUI program.
Ex: An artificial kidney to demonstrate dialysis.
Mould can be made up of plastic material to stimulate some life in objects. ex: body which shows evidence of trauma, infection, disease, surgical intervention.
IMAGE PERSPECTIVES' MOULAGE PROCESSThe basic material we use to create our soft tissue injuries is very inexpensive; it costs only pennies per simulation.
If someone walks off with a simulation it can be recreated in a matter of minutes!
You are not limited to mass-produced latex or plastic "one-size-fits-all injuries". You determine the type, scope and
Size of the injuries and create as many as you wish, in whatever size you need.
Our simulations can be handled and bandaged, with care, as you would a real injury. The simulations will not shift and/or be damaged. When bandages are removed, the injury simulation will remain intact.
The simulations can be made liquid-proof, and with care - reusable!
One of the old and popular arts in Indian villages is puppetry. Puppetry is an education cum entertaining aid in which puppets manipulated by the performer is a person termed as a characters in a story to be depicted.
A puppet is a manipulative doll dressed as a character and the performer is a person termed as a puppeteer. A good puppeteer has to blend his art with dramatization to produce the desired effect. It is used as an effective teaching aid for languages and social sciences.
Types of puppets
1. String or marionettes puppets:-Marionettes consist of puppets with hinged body parts which are controlled by nine strings produces required movements in the puppet. These puppets are mainly manipulated by professional puppeteers.
2. Stick puppets: - stick puppet are the painted cutouts attached by sticks. The actions of these puppets are manipulated by the teacher and students by hiding behind a screen so that only puppets are visible to the audience or the class.
3. Shadow puppets: - shadow puppets are silhouettes of cardboard which produce shadows on white screen. The motion of these silhouettes is manipulated by the teacher and students.
4. Finger of hand puppet: - Hand puppets are round balls painted as heads with overflowing colorful costumes. These are worn on fingers which operate their movements. These are operated from below the stage.
A chalkboard or blackboard is a reusable writing surface on which text or drawings are made with chalk or other erasable markers.Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. Modern versions are often green or brown and are thus sometimes called a greenboard or brownboard instead.
A blackboard can simply be a piece of board painted with matte dark paint (usually black or dark green). A more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade chalkboards are made of a rougher version porcelain enameled steel (black, green, blue or sometimes other colours). Porcelain is very hard wearing and chalkboards made of porcelain usually last 10-20 years in intensive use.
Blackboards have disadvantages:
They produce a fair amount of dust, depending on the quality of chalk used.
Some people find this uncomfortable or may be allergic to it, and there has been speculation about links between chalk dust and respiratory problems.
The dust also precludes the use of chalk in areas shared with dust-sensitive equipment such as computers. However, these alternative methods of displaying information have drawbacks of their own.
The scratching of fingernails on a blackboard is a sound that is well-known for being extremely irritating.