Relative effectiveness of using instruments versus freehand drawing when teaching descriptive geometry

Abstract

Industrial education programs are currently faced with an ever-increasing base of technological information and are finding it difficult to present a comprehensive curriculum in the time available. This has created a need for developing more efficient teaching methods to accommodate the greater amount of information to be covered. The purpose of this investigation was to determine the effects of two methods for learning concepts of basic descriptive geometry. In one method the students completed all drawing plates using freehand drawing; in the other method, the students completed the same drawing plates in a traditional manner, with the aid of drafting instruments. A comparison of these methods would attempt to answer questions regarding whether freehand drawing or instrument-assisted drafting was more effective in terms of cognition of technical material dealing with basic descriptive geometry, and whether any significant differences existed in time required to complete selected descriptive geometry drawing problems. The study was conducted using two sections of Engineering Graphics IA 104 at Millersville University. A modification of the Randomized Control-group Posttest-only Design was utilized. The students were randomly assigned to either the freehand drawing method or the instrument-assisted drafting method in each section. The treatment involved the completion of eight basic descriptive geometry drawing plates, with one group completing all problems by the freehand drawing method and the other group completing all problems by the instrument-assisted drafting method. The times for completion were recorded for all drawing plates. A posttest was then administered to determine knowledge acquisition for each group. A two-way factorial analysis of variance was performed on all data, with the following results being apparent: (1) There was no significant difference in cognition between the freehand drawing method and the instrument-assisted drafting method, as measured by the posttest. (2) Students completed the eight drawing plates in significantly less time while using the freehand method, compared to the instrument-assisted method. Therefore, it was concluded that the freehand drawing method for learning basic descriptive geometry would appear to be a more efficient method of instruction in terms of the time required.