ON THE FORMATION OF ACTIONS OF PROJECTION-CONSTRUCTION OF THE TECHNICAL DRAWING AND ITS TEACHING

Abstract

The purpose of the present study was to examine the method of teaching, by which middle grade school children could draw and read the orthographic views (third angle projection) with forming actions of projection (P) and construction (C).
On the base of preliminary experiments, the training program of 23 steps consisting of the following 5 blocks was produced.
In the first block of training (step 1-8), children learned to draw the three orthographic views (front, right-side, and top views) of a point inside a three-dimensional-cordinate frame (the projectograph). Afterwards, they learned to construct a point in the frame through reading three views being given as tasks.
In the second block (step 9-11), they learned to draw the three views of a straight line inside the frame, and then learned to construct a straight line in the frame on the three views.
In the third block (step 12-16), they learned to draw the three views of cubes inside the frame, and then learned to construct cubes on the three views of them without the help of frame.
In the fourth block (step 17-21), they learned to transform the isometric drawing into the orthographic views and vice versa.
In the last block of training (step 22-23), they learned to produce and draw the three-dimensional figure image for an object through reading orthographic views of it, and then learned to rotate 90° and 180° to the right or left mentally before drawing it.
Based on performance levels of projection and construction tests for 43 school children in third grade, 8 pairs of matched Ss who had no knowledge of the orthographic projection and had not yet acquired the actions of P and C were selected, and were assigned at random to each of the experimental and control group.
8 children in experimental group (8:1-9:0) were trained individually in accordance with the training program for about three months, but 8 children in control group (8:1-8:11) underwent only the control tests periodically without any training.
As results, the following facts were ascertained:
1) Under the training program, even middle grade school children could acquire the ability of Euclidian spatial representation.
2) Ex. gr. children were able to learn the actions of P and C, necessary for the learning of the technical drawing.
3) Especially, they could acquire the ability of spatial representation enabling mentally the rotation higher of the produced image through reading orthographic views to some directions.
4) But the acquired spatial ability of children by the training program remained at a level influencing partially on the solutions of Piaget's “three mountain tasks” and tasks of the projection of straight lines.
In conclusion, this experiment suggested the high possibility of teaching enabling middle grade school children to draw and read the orthographic views under the condition of an elaborated training program.