Graphic aids are charts, diagrams, graphs, maps, flashcards, posters, pictures, photographs, leaflets, folders, pamphlets, cartoons and comics. They are two-dimensional materials having no depth which communicate facts, ideas and relationships clearly through words, lines, drawings, symbols and pictures. Graphic aids can serve many educational objectives for group teaching of 20 to 30 students. They help to:
1. Visualise abstract concepts which are difficult to understand - concepts of size, rate of growth, inner structure of an object or machine etc.
2. Reduce the amount of verbal talking and help in giving clear explanations; visuals in charts, graphs, diagrams and posters, cut down words.
3. Present the information in a specific and systematic manner. Since majority of them are formal aids, they have to be very systematic and organised.
They are also popular because they are
1. Comparatively less expensive.
2. Easy to make as no technical skills are required. Regular teachers, with some knowledge of drawing and who desire to be creative can prepare them.
3. Easy to use. Very special arrangements and machines are not required.
4. Easily usable and reusable as they are flat, two-dimensional materials.
Graphic Aids - I
This section includes those graphic aids which have similar principles of preparation, presentation and storage, and can be employed to do serious classroom teaching in home science.
A graph is a diagramatic representation of numerical or quantitiative data. Graphs can be in many forms.
In an area graph, the simple kinds of comparisons for approximate and not exact differences in size can be made. Two-dimensional, geometrical shapes such as squares, circles, rectangles are used to compare two or three items.
In a solid graph, three-dimensional, geometrical or pictorial symbols of any other shape are used for comparison. It is more difficult than the area graph as the comparison is to be made in terms of volume instead of area.
A line graph, also known as a 'curve' graph, is the most appropriate type to represent two related data in an exact and complete manner. It is mostly used to combine quantity with time
to show progress, change and development of more than one data.
A bar graph is simple and easy to construct and is used to
make comparisons of two or more data. It has a zero base and the data is plotted with the help of horizontal or vertical bars. The length of the bar represents the amount in terms of percentages, calories, grams, mean, etc.
A pie graph is also known as 'Circle graph' or 'Sector graph'. Pie is the circle representing the total numerical amount and each slice is a specific percentage. It is ideal for showing fractional relations. However, it is difficult to prepare and to understand if the segments or percentages are too small, too many or too similar.
The students learn better if actual percentages are included on the slices instead of letting them judge by the size of the slices.
In a pictorial graph, conventional self explanatory symbols are used instead of erecting bars. It is mostly used when the purpose is to advertise, publicise, or motivate people for some action or product. The simple pictorial symbols suggest rather than represent. A pictorial graph:
1. shows number rather than size for indicating quantities.
2. compares rather than shows isolated elements.
3. shows approximate quantities and not exact amounts. So, though it provides realism, it cannot:
4. be read quickly.
5. provide precise information.
6. show fractional percentages.