Audio-visual aids in extension

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The term audio-visual aid refers to anything that an extension agent uses to help to convey the message when communicating with farmers. The spoken word is the agent's main communication tool, but, whether the agent is speaking to a large village meeting or discussing a problem in a field with a group of farmers, its impact and effectiveness can be greatly increased by the use of suitable audio-visual aids. When selected and used properly, audio-visual aids can help in the following ways:

- The interest of the audience can be maintained if the agent varies the mode of presentation. It is difficult to concentrate for long on what someone is saying; but if the agent refers to a wall chart, or illustrates a point with some slides, his audience's attention can be maintained.
- When information is presented to more than one sense (sight and touch, for example, as well as hearing), more is taken in and it is better understood and remembered.
- Processes and concepts that are difficult to express in words alone can be explained. The procedure for applying for a loan, for example, may sound confusing, but a simple chart or diagram can make the process clearer. Again, the life cycle of a crop pest can be explained by showing a series of slides or drawings.
- The effects of decisions and actions that farmers might take can be shown. Photographs of a cattle dip or a model of a cooperative store can give farmers a clear idea of just what it is they might be considering.
- Pictures can have a more immediate impact on our emotions than words. Photographs of a heavy crop, for example, are likely to arouse interest more effectively than details of yields read out by an extension agent.

The range of audio-visual aids

Extension agents often use sophisticated audio-visual aids which require electricity and complex machinery such as projectors or television sets. But there are many simple aids that the agent can make locally, and these have several advantages. They do not require a power source or heavy equipment, they do not cost much to produce and they can be made to suit the precise needs of the agent. Between these two extremes lies a wide range of more or less sophisticated aids. The distinction between a mass medium and an audio-visual aid lies only in the way it is used. All the mass media described earlier can be used as audio-visual aids. A film is a mass medium, in that it is shown to large audiences in many different places; but for an individual extension agent who uses it to increase the impact of a talk, it is an audio-visual aid. Many of the principles of media use discussed earlier also apply to audio-visual aids. The audio-visual aids available to the extension agent can now be examined.


A real object is often the most effective aid. It enables the audience to understand exactly what the extension agent is talking about. Equipment and tools can be shown, samples of diseased plants and insect pests displayed and different seed varieties and fertilizers handled by farmers.

Where an object is too large to be shown, a model of it can sometimes be used as a teaching aid. This applies particularly to buildings and other fixed structures. The construction of a poultry shed, for example, or the installation of a dip tank can be demonstrated by using a model, which can be taken to pieces in front of the audience.

Photographs offer another substitute for real objects. They can be passed around an audience or displayed by the agent. If a photograph is being taken to use as a visual aid, just the right amount of detail should be included for the audience to recognize it. Too much detail confuses and distracts, while too little prevents recognition. Photographs of people doing things are more likely to interest the audience than photographs of objects alone.


Blackboards are widely available in schools, rural training institutes and extension offices. They may be fixed to an inside wall or supported on a freestanding easel which can be moved around. They are useful for setting down the main headings of a talk, for sketching simple drawings and diagrams, and for noting points raised in questions and discussion.

If using a blackboard, the agent should practice writing on it, if necessary by drawing horizontal chalk lines for guidance. He should make sure that the writing is large enough for someone at the back of the audience to see clearly and that the headings and phrases are kept short. There is not much space on blackboards and the agent will lose the audience's attention if he spends a lot of time with his back to them while writing.

Whiteboards have a smooth, shiny surface on which coloured felt pens can be used, but it is important to use only pens with water-soluble ink. Whiteboards are easier to use than blackboards from both the agent's and the audience's point of view. The pens flow smoothly over the surface and the colours are much clearer than chalk on a blackboard.

Newsprint, which is an inexpensive paper, can be obtained in large sheets and fixed to a blackboard or to the walls of a building. It can be used in the same way as a blackboard but it is more versatile. Text and drawings can be prepared on several sheets, before a meeting, to avoid having to write while speaking. Paper and pens can be given to small discussion groups to note their conclusions. These conclusions can then be displayed around the meeting-place and discussed by others. Suggestions and ideas from the audience can be added to enable farmers to see their decisions taking shape. Used sheets can be kept for future reference. At a planning meeting with a group of farmers, for example, the agent can take away the sheets to guide him in preparing a written record of the decisions taken.


Posters are useful for highlighting the main theme of a talk and wall charts can be used to show complex processes. Although they are used mainly in class-room teaching where they can be left on the wall for future reference, they can also be carried by the extension agent to help him to convey ideas to farmers.

Flip charts

Flip charts contain a series of pictures, with or without words, fastened along one edge between two sheets of thin wood or thick cardboard. The two covers can be opened and folded back so that the flip chart stands in front of the audience. Each picture illustrates one point in the extension agent's talk and he simply turns over each one when he moves on to the next point. As well as helping the audience to understand and remember they remind the agent of the structure of his talk without the need to refer constantly to his written notes.

Many extension agents will already have access to printed posters, wall charts and flip charts, but they can also be made locally with large sheets of paper and coloured pens. When making flip charts, the following points should be noted.

- Lettering should be large.
- Diagrams should be simple.
- Information on each sheet should be limited.
- Pictures from posters and magazines can be cut out and stuck on by those who cannot draw.
- Pre-testing is important for all home-made visual aids.


A flannelgraph is made from rough textured cloth, such as flannel or a blanket, which is hung or supported almost vertically. Figures, words, and symbols cut from cardboard, which are backed with similar cloth or sandpaper, are attached to it. A cheaper backing is obtained by putting glue on the back of the cut-out and then dipping it into fine sand. The backing holds the cut-outs firmly on the cloth surface. The cut-outs are prepared beforehand and can be used repeatedly.

The flannelgraph can be used very effectively to build up a story or an explanation. Unlike a wall chart, which can confuse an audience by presenting a finished diagram at the start of a talk, a flannelgraph can be used to present in turn each part of the diagram until it is complete.

The cut-outs can be placed in different positions to show alternative outcomes. After showing the process of wind erosion, for example, the effect of wind-breaks can be demonstrated by placing cut-outs of trees between the wind direction and a field. Arrows representing the wind can then be deflected, and the general effect shown by putting back soil symbols on the surface of the field.

A modern alternative to flannelgraphs is the magnetic board. Cutouts are backed by a magnetic strip, that holds them firmly to a metal board. They can be used in windy conditions when flannelgraph cut-outs would blow away, but they are cumbersome to transport. On the other hand, flannelgraphs, which can be made in a variety of sizes and designs can be folded into an agent's bag or rolled up and tied to a bicycle.

Projected aids

Films, colour slides, filmstrips and overhead projector transparencies are useful as teaching aids, bringing colour, variety and interest to an extension talk. However, they all require specific equipment and electricity. Extension agents are, therefore, more likely to use them in training centres and schools, although some slide projectors can be adapted to work from a 12-volt car battery. Films, filmstrips and slides are best used at night or in a room with curtains drawn or shutters closed. Daylight screens can be used for small groups. Overhead projectors can be used in daylight, provided the sun is not shining directly on the screen or wall on which the image is projected.

Colour slides can be selected and put in a suitable sequence by the extension agent. He can produce his own slides to suit his purposes, provided he has access to a camera, film and film processing facilities. A slide set can easily be modified or updated by replacing one or more slides. If they are kept dry and free from dust and fingerprints, they will remain in good condition for many years. An agent can either provide his own spoken comments on the slides, or a commentary can be recorded on an audio cassette. With synchronized equipment, the tape can be modified so that slides automatically change at the appropriate point.

Filmstrips contain a sequence of slides in a single continuous strip of film. They are shown on a slide-projector fitted with a filmstrip carrier between the projector body and the lens. They cannot be modified easily and the sequence is fixed, but individual frames cannot fall out or be put into the projector the wrong way round. They are useful when a fixed message has to be presented many times.

Overhead projectors are usually only found in class-rooms. Diagrams and texts are put on to a sheet of transparent acetate with special felt pens; the acetate is then placed on a flat glass platform through which a light shines, projecting the contents on to a vertical screen. The agent can write on the acetate while facing his audience, or he can prepare it beforehand. If he covers different parts of a sheet with paper, he can gradually reveal the sections of a diagram, thus achieving an effect similar to the flannelgraph.

Using audio-visual aids

Audio-visual aids are only effective if they are appropriate to the situation and are used properly by the agent. Unsuitable aids or ones that are not used properly can at best distract and at worst mislead the audience. When selecting suitable audio-visual aids, the agent will be limited to what is readily available or can be made. Within that range, some aids are more suited to a particular objective than others. For example, if accurate detail is needed, a photograph, slides or a careful drawing may be more appropriate. If, on the other hand, the agent simply wants to highlight the structure of a talk or the main conclusions of a discussion, a blackboard or newsprint will be suitable. The agent should also consider where the aids will be used: indoors or outdoors, with or without electricity, at a large meeting or with a small group. All these factors will influence the choice of audio-visual aids.

Proficiency in using audio-visual aids cannot be learned from a book; it comes only with practice. The following principles may, however, be useful, whatever audio-visual aids an extension agent may use.

Select the aids most in accordance with your objective, the composition and size of the audience where the aids will be used.
Use the aids to reinforce your message. They are there for support, to complement and supplement the spoken word, and should not be expected to communicate their contents without explanation. Refer to them, explain them and ask questions about them.
Make sure that the audience will be able to see and hear clearly. Audio cassettes that cannot be heard or lettering that is too small to be seen can make the audience restless and inattentive.
Practise using the aids beforehand. Where projected aids are used, it is important to be completely accustomed to the equipment. For example, there are seven incorrect ways of loading a slide into a projector but only one correct way.

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