Diseño de la investigación.

As in tracing treated above, copying is not far-fetched too. Copying can be referred to as a method of reproducing diagrams with the same size. It can also be proportionately enlarged or

reduced. There are two basic methods of doing this. They include:

(a) the grid method

(b) the pantograph method.

(a) The Grid Method

This method is very easy done in that it gives room for the reproduction of an existing drawing, symbols, letters etc. It employs squaring method whereby the original image is

subdivided into squares/units. The lines of the squares are called a grid system or pattern.

Original drawing can be enlarged, reduced or drawn in the exact size using this method.

See the figure 9 that follows.

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Fig. 9:

Original

Steps involved in Copying

(1) Square up the original as above.

(2) Square up the surface onto which the drawing is to be copied.

(3) Ensure that it is relevant to the desired size.

(4) Number both the horizontal and vertical lines.

(5) Place the original copy in front and copy its content to the new squared sheet.

(6) Be as accurate as possible and juxtaposed the two drawings eventually.

Enlargement Process

In case of enlargement, all you need do is multiply the original size by the number or level of enlargement. For instance, the vase drawn above is to be enlarged to thrice the original size.

Then the new squares will be three times as big as the original squares.

Reduction Process

This is just the opposite of the above enlargement process. For instance, if you are to reduce the

original by one quarter (¼), then the new squares that you draw have to reflect this by being divided by 4.

(b) Pantograph Method

This method employs the use of an instrument called pantograph. A pantograph is a simple copying device used to make an enlargement, reduction or a copy of the exact size

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for reproduction of drawings. It is made of an assemblage of four pieces of wood, metal

or plastic bars. Each bar contains a series of calibrated holes. By hinging these bars together at certain predetermined points, several ratios in enlargement and reduction can

be realised depending on the model.

Keys:

a  pivot point d

Method of using the Pantograph e

a

c b  tracing pin

c  pencil for drawing d  differential ratio point b

(1) (2) (3) (4) (5) (6)

A broad and smooth working surface is required.

Fix the pivot point at the lower left corner of the working surface.

For enlargement, fix the tracing point at B.

Pencil should be fixed at point C.

The tracing point should be used to trace over the original.

Support the drawing with the other hand as you are drawing.

To Reduce (a)

(b) (c)

Reverse the position of the pencil from c to b and the tracing pin from b to c.

Carefully trace with tracing point now at c and the pencil at b will reproduce a reduced drawing.

Note that changing the hinging position at d and e will change the ratio of enlargement or reduction.

To Copy Exact – Size (a)

(b) (c) (d)

Locate pivot point at b Locate tracing point at a Pencil position should be at c

By this the original picture will be transferred to a.

Self Assessment Exercise 1.1:

(1) Describe the arrangements of materials to be traced in each of the three tracing techniques?

(2) With the aid of tracing paper, trace any drawing of your choice from a textbook. Make flash cards without destroying the book.

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(3) Specify the difference between tracing and copying.

4.0 CONCLUSION

It is not advisable to teach a child how to eat fish, but teach him/her how to fish. Every teacher should seek to think outside the box, in order to bring a lot of innovations to the teaching career

through the use of common and locally produced materials. The simple production techniques as

described are straight forward and practicable. As already known, please note that teaching is incomplete without the use of locally produced instructional materials.

5.0 SUMMARY

As we have discussed, a locally produced instructional material should have relevance, appropriate and validation as added advantages over the commercially produced ones. With persistent practice, you will sharpen your skill in the area of production of instructional media.

In addition, the three types of production of instructional media are necessary in utilising media production.

6.0 TUTOR MARKED ASSIGNMENT

Mention the three types of production of instructional media that are necessary in utilising media production.

7.0 REFERENCES AND FURTHER READINGS

Abifarin, M.S. (2004). Modern Approach to Educational Technology, Lagos: Inter-venture Publishers Limited.

Abimbade, A. (1997). Principles and Practice of Educational Technology, Ibadan: International Publishers Limited.

Adewoyin, J.A. (2004). Fundamentals of Educational Technology, Lagos: Raytel Communications Limited.

Ajelabi, A. (2005). Essentials of Educational Technology, Lagos: Raytel Communications Limited.

Salawu, I.O., Afolabi, A.O. and Taiwo, S.A. (2001). Essentials of Educational Technology, Oyo:

Kay Blessing Ventures.

Salisu, S.O. (2002). Educational Technology: A Theory and Practice Course Text, Lagos: Ikofa Press Limited.

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UNIT 2 IMPROVISATION