Teaching Part Visualization In First Year Engineering Courses: General Scheme For Part Visualization Problem Solving

Part visualization is a fundamental skill in engineering. It refers to reading and understanding any technical drawing, interpreting different views of an object/assembly which has been represented on a standardized drawing. However, engineering students show certain learning difficulties and a high failure rate in subjects such as Technical Drawing and Design. The main aim of this study is to introduce a new teaching strategy for part visualization. A problem solving model for visualization has first been designed for all kind of industrial objects (Methodology for Part Visualization Problem Solving) with a constructivism view. Teaching strategies may then be applied by drawing up a programme of specific tasks which takes into account the theoretical contents and procedures involved in part visualization and students’ main difficulties and deficiencies when solving this kind of problem. ICTs (Information and Communication Technology) and real models have been used in classroom to help the students link the 2D drawing with the 3D object/assembly. After testing the method in the classroom, the results which have been obtained from experimental and control groups test have been contrasted, showing an important improvement (fewer drop-outs and a higher percentage of students who have passed the course). In terms of comprehension of part visualization, the percentage of students who have passed the specified exams has been higher than the control group and the average grade has been higher as well. It is worth noting that every student has an improvement of 10% on their grade in the comparisons made between the first visualization quizzes and last ones completed in the first trimester. These positive but not statistically significant results encourage us to keep improving the teaching-learning process of the part visualization. This study has been done in the first course of Industrial Engineering in the Faculty of Engineering of Bilbao in the The University of the Basque Country. The subjects of the study have been selected randomly and the students do not know that they have been part of a study. P ge 13170.2 Why this intervention? There are three main reasons that justify this didactic intervention: In the subjects of engineering, difficulties are observed in the visualization of parts and the development of spatial capacities throughout the course (Sierra Uria, Egoitz, 2005)1. The ability to mentally visualize and manipulate objects and situations is an essential need in many jobs and careers. It is estimated that at least 84 majors consider the spatial visualization a fundamental need (Smith, 1964) and in technical jobs, such as the different types of engineering, the abilities to visualize are especially important (Maier, 1994)2. The third reason that justifies this study is that educators need to continually analyze and investigate their own teaching to be more effective educators (Fernando Hernandez, 1992) 3. Previous analysis and current situation The visualization of parts in the multiview projections system, in other words, the interpretation of views of an object represented by its technical drawing, is a fundamental skill in the engineering career, and in the learning of the Technical Graphic subject, because if a student is unable to visualize, then he/she will not be able to continue mastering the rest of the content of the subject. It is necessary to analyze the specific difficulties that arise in the learning of visualization. Educators have often noticed the difficulties of most students in graphic courses when trying to visualize an object using multiview drawings. This is mainly due to the inexistence of a systematic process to analyze complex forms (Luzzader y Duff 1986) 4. We also find students that haven’t developed their spatial capacity enough and therefore have serious difficulty understanding and manipulating the parts in space (Navarro,2004)5 . One of the main causes could be the didactic strategy followed in most classrooms, which consists of visualization problems followed by the solutions to those problems, without explaining how to solve them or the reasoning needed during the problem-solving process (Garmendia, 2004) 6 . The students confirm not having a problem-solving strategy, and that they use the trial-and-error strategy instead or they rely on intuition. On the other hand, a review of the literature of technical drawing textbooks has not been successful in finding a clear, concise, and developed method of solving visualization problems using procedural contents. Sierra Uria, Egoitz, 20051 . P ge 13170.3 Even the most advanced engineering students in other subjects, encounter difficulties comprehending the mechanisms that relate the representation of three-dimensional objects to their reality (Pérez Carrión y Serrano, 1998) 7. Students affirm comprehending the theoretical aspects but they have trouble with procedural techniques and reasoning while solving visualization problems. In this sense, this didactic study in problem-solving affirms that when students reason, different aspects of inter-related knowledge are put to work. A set of general abilities is used and applied to concepts of a subject, creating particular ways of reasoning in that subject. Therefore, the didactic study affirms that, besides the theoretical and conceptual knowledge, another content such as procedural knowledge must be considered in teaching (Guisasola et al. 2003) 8. This study proposed a problem-solving model9 , adapted to the case of object visualization, integrating resolution structure, concepts, procedures and different types of reasoning specific to visualization. Didactic research provides evidence, even more so in recent years, of the inefficiency of conventional teaching methods. The notion that the knowledge of the professor can be transmitted in its final stages (by stating a problem and showing how to solve it based on the solution) is not the best way to help the students ́ learning process. Teaching scientific knowledge in the final stages in an organized manner does not prevent failure in learning concepts and problem solving. (Maloney 1994) 10. When planning the teaching of specific content and deciding the design of the learning process through an activity program, it is necessary to define certain aspects. Among these, the intended objectives and the contents, keeping in mind the possible difficulties that can arise in the assimilation of the content by learners. But at the same time, it is necessary to define the strategy that will be followed to improve the meaningful learning, defining a logical sequence of activities designed expressly for the learning process, as well as the type of assessment that will be used to improve and orient the learning. On the other hand, another factor related to the visualization of parts is the spatial capacity. Mathewson (1999)11 affirms that educators often forget the factor of spatialvisualization in learning. A review of most of the text books in the subject show that little is done to improve the development of the spatial capacity. The engineering textbooks present often orthogonal views, static concepts, theories and ideas with little or no explanation, and no interpretation of spatial data. It is assumed that the student will be able to overcome the mental challenge, assembling the spatial puzzle. Currently the ICTs (Information and Communication Technology) offer complementary tools for the learning of every subject, therefore, for the visualization of parts. Agreeing with Bertoline et al. (1995) 12, one way to improve the ability of the student when P ge 13170.4 visualizing an object or a 3D scene is to make his/her experience as realistic as possible. The ICTs have permitted the apparition of new working tools, such as the VRML (Virtual Reality Modeling Language) or the X3D, that enable the interaction with objects through a virtual world, lowering the difficulties of comprehension between the spatial reality of a part and its representation on the technical drawing. As Mc Lellan affirms (1998)13 , virtual reality is a cognitive tool that permits the immediate dynamic interaction, making it possible for the student to comprehend the engineering concepts that are spatially dependent. According to a number of authors, in order to increase the spatial capacity it is necessary to work with 3D models in space wich can be turn, move, and work on mentally, for example by obtaining their projections (Devon et al. 1994) 14 According to Potter (2003)15 the students with a deficient development of spatial capacity, need to learn, by using static, dynamic and transformational images, as well as their combined use in problem solving. The spatial perception can be developed in many ways, including: modeling and freehand drawing of objects, representing objects in 3D models, manipulating objects in 3D, in order to recreate their representations dimensionally, finally experimenting and working with different perspectives or views of the represented part or object both on the blueprint and in the computer image. I Bertoline, 200316 As Wolfram(1994) 17 writes, people only remember 15% of what they hear, and 25% of what they see or watch, but they do remember 60% of what they interact with. Therefore, educators in engineering schools should start using interactive multimedia tools in their curricular content.(Mohler,2001) 18 Intervention characteristics The intervention was conducted under a constructivist focus and under the European frame of higher education, and was characterized by the following: ‚ Basically the problem-solving process was used to solve visualization problems, working on the PROCESS (avoiding problem-solution) P ge 13170.5 Methodology for Part Visualization Problem Solving P ge 13170.6 ‚ Sketch: Sketching is used explicitly because it is a very important and a necessary capacity and as a means to double check what has been visualize