To cite this document: SPERANZA, D., BARONIO, G., MOTYL, B., FILIPPI, S., & VILLA, V. (2017). Best practices in teaching technical drawing: experiences of collaboration in three Italian Universities. In Lecture Notes in Mechanical Engineering - Advances on Mechanics, Design Engineering and Manufacturing (pp. 903-913). Springer International Publishing. ISBN 978-3-319-45781-9, doi 10.1007/978-3-319-45781-9_90, http://dx.doi.org/10.1007/978-3319-45781-9_90
Best practices in teaching technical drawing: experiences of collaboration in three Italian Universities Domenico SPERANZA1, Gabriele BARONIO2, Barbara MOTYL3, Stefano FILIPPI3 and Valerio VILLA2 1DICEM
Dept. - University of Cassino and Southern Lazio, Cassino, Italy Dept. – Università degli Studi di Brescia, Brescia, Italy 3DPIA Dept. – Università degli Studi di Udine, Udine, Italy 2DIMI
*Domenico Speranza. Tel.: +39-776-239-3988. E-mail address:
[email protected]
Abstract This work present some best practice cases in teaching technical drawing done by three Italian Universities: Brescia, Udine, and Cassino and Southern Lazio. The intention to innovate and improve the basic technical drawing courses offered by these three Universities started in 2014. The objective of this collaboration was the development of some tools to help the students in understanding the fundamental concepts of technical drawing. The first tool developed, in order of time, was the Technical Drawing Evaluation Grid – TDEG. Starting from this tool, other learning aids were developed for the undergraduate engineering students. Some of them are: an online test for students’ self-assessment of technical drawing knowledge; a questionnaire to collect students’ opinions on different technical drawing and engineering design topics; a method for the improvement of students’ motivation to study; and a self-learning tool for teaching manufacturing dimensioning. The preliminary results of these different practices are presented and discussed in the following, posing the basis of the definition of some best practice methods that can be used for the improvement of the teaching and learning of technical drawing basic concepts for engineering students. Keywords: technical drawing, teaching & learning tools, best practices, collaboration.
2
1 Introduction Since 2014, the research groups of the Universities of Brescia, Udine and Cassino started a collaboration on technical drawing education. This collaboration aimed at the improvement of the quality of teaching, and of the acquisition of specific technical skills by engineering students [1, 2, 3, 4]. One of the particular objectives of this collaboration was the development of some tools to help the students in understanding the fundamental concepts of technical drawing as: projection methods, use of standards, and dimensioning and tolerancing – GPS/ GD&T. For these reasons, different kinds of educational tools were developed, applied and tested during the technical drawing courses offered by these three universities. Usually, technical drawing courses involve engineering students enrolled in the first year (Brescia and Cassino) and in the second year (Udine) of the Bachelor degrees in Management and Industrial Engineering. The courses’ contents and the number of hours dedicated to the in-class lessons and exercises are similar and comparable: 56 hours in Brescia and Cassino, and 60 hours in Udine. All of these courses three are basic courses on Technical Drawing - TD, moreover they are attended by a large number of students. Generally, a large portion of the enrolled students does not have any a priori knowledge of the topics proposed because of their school of origin. This way, it is important to highlight that TD is the basic language for these future engineers, and it is used to deal not only with the other following engineering courses but also, especially for their future employment. Conversely, experience and skills, acquired during the subsequent courses, such as mechanical technology, engineering design, allow a better understanding and application of the rules of TD in general. In this context, the TD instructor is forced to anticipate, in a qualitatively way, some topics related to these courses to allow the students a better understanding and application of certain standardized rules and conditions. Thus, the main purpose of TD courses is to standardize the level of knowledge of TD and engineering graphics principles, focusing on different drawing tools as orthogonal and isometric projections, sectional views, dimensioning rules and practices, and the introduction of related drawing and international technical standards (ISO, EN, or UNI). Starting from these considerations, Brescia, Udine, and Cassino Universities have established a collaboration based on of the use of the Technical Drawing Evaluation Grid – TDEG –, developed by the University of Brescia [5]. The TDEG represents a proposal for an assessment grid of the learning levels for TD both in academic and in industrial contexts and it is based on the European Qualifications Framework -EQF. The basic idea of TDEG is to consider TD as a language. This way, as we can use a reference grid for the different levels of language knowledge we can use a reference grid for the evaluation of the knowledge and acquired skill in TD. Thus, TDEG may be used as a reference framework for TD education both in national and international contexts and in formal, non-
3
formal, or informal learning and education initiatives. Moreover, TDEG may constitute a guideline for learning paths in engineering design and it may be a useful tool to recognize skills and abilities in corporate contexts and to represent a reference point for the design of the engineers’ curriculums. The structure of TDEG follows the original eight levels of EQF, which have been split into two sub-levels A and B, for an example see Figure1. These two sub-levels represent skills and competences that a person may acquire in each level. This was made in analogy with the “comprehension” and “production” used in foreign language assessment grids. The A sub-level is related with TD used as a pure communication language, with special reference to TD understanding capability. The B sub-level is related with the capability to produce correct technical drawings aimed to design synthesis [5].
Fig. 1. An example of TDEG levels: Level 1, extract from [5].
In the next section, some of the developed best practice experiences are described.
2 Examples of best practice experiences in teaching Technical Drawing
2.1. Online test for self-assessment on Technical Drawing. During the 2014-15 and 2015-16 academic years, the students of Brescia, Udine and Cassino Universities were asked to participate to an online test for selfassessment on TD. The main goals of this test are to provide students with a tool for self-assessing their knowledge of the basic TD rules, and principal standards and to give teachers some feedback on the different TD topics. The test is designed to be managed and administered by the Moodle platform, customized by CINECA [6, 7]. The test is composed of 15 multiple-choice closed
4
questions, which are related to the first six levels of knowledge of TDEG. In particular, there are four questions for Level 1, three for Level 2 and Level 4, two for Level 3 and 5 and one for Level 6. Each question has six answer options, five are predefined responses, among these answers, only one was correct, and the others are completely wrong or inaccurate. The sixth option considers the possibility of not answering the question. Some of the questions are only in text format, others are illustrated using technical drawings, see Figure 2.
a)
b)
Fig. 2. A) An example of a text question; b) an example of an illustrated question.
The students have 15 minutes to complete the test and, during the execution they are guided by a navigation quiz toolbar were the progressive numbers of the questions and a timer are highlighted. At the end of the test, students can view immediately the results and can navigate through the questions to see the correct and the wrong answers. For each correct answer is assigned a value of +1. For each wrong answer is assigned a value of - 0.25. If students do not answer to a question the value assigned is 0. This way, if a student responds correctly to all questions he can reach the maximum of 15 points, which are then converted into a vote equal to 30/30. To pass the test a student must take at least 9 points corresponding to a vote equal to 18/30.
5
Table 1. Significant data of online test students’ participation. University
N° of students participating to the test in a.y. 2014 -15 (% of participation)
N° of students participating to the test in a.y. 2015 -16 (% of participation)
N° of students’ attempts in a.y. 2014-15
N° of students’ attempts in a.y. 201516
N° of passed test in at least 5 attempts
Mean vote in passed attempts
Brescia
61/120 (51%)
-
272
-
46/61
23.75
Cassino
-
124/150 (80%)
-
445
60/124
22.00
102/160 (64%).
-
171
-
54/102
21.89
Udine
A maximum of 10 attempts was set for each student, and the fifteen questions are shuffled for each different attempt coming from a DB of about 250 questions. This test was developed by Brescia research unit and was adopted for Brescia, Udine and Casino students. Now quite 300 students participate to the test. In Table 1 are reported preliminary results. This experience has proved to be very positive and the students of the three seats appreciated it. The percentage of participation to the test was significant. In fact, more than the 50% of the students have taken the test using this self-learning tool both in the initial and in the final phases of the course, especially as a checking tool their knowledge before the final exam. Similarly, it is a very useful tool also for teachers, because they can monitor the students’ progress and they may identify potentially difficult topics, which need further clarification. At the moment, the statistical analysis of the data collected by the three seats is in progress.
2.2. Online questionnaire on technical drawing Still, during academic year 2015-16, in all of the three universities, students of TD courses were asked to answer to an online questionnaire on TD. The main goals of this survey were to collect the different opinions of the students on some topics related to TD skills and competences and to other issues [8, 9]. In particular, the questionnaire is composed by twenty-three questions, sixteen of them are close questions related to skills and competences, which students may acquire during TD courses. Then, other four questions are related to the “digital behavior” of the students in relation to digital technologies and their practice or with the innovative 3D printing theme. Finally, there are one closed question
6
about the students’ expectations of TD course in terms of knowledge improvement, and two open questions, one is related to the possibility to participate to a design competition and, the other asks students’ personal opinion on TD in general. Table2. Preliminary results of the online questionnaire. University
N° of students participating to the questionnaire in a.y. 2015 -16
% of participation
Brescia
52/102
51%
Cassino
116/150
77%
Udine
77/133
58%
As can be seen in Table 2 the number of student participating to the survey is relevant, more of the 50%. The preliminary results of this work highlight the interest of students for TD in general and for both handmade TD techniques and 3D CAD modelling. Moreover, some interesting aspects concerning the “digital behavior” of the students emerged. In particular, the students’ relationship with digital devices and their level of knowledge of innovative topics as 3D printing, may be interesting for future research and teaching improvements.
2.3. Interactive self-learning tool for teaching manufacturing dimensioning The Technical Drawing Learning Tool–Level 2 - TDLT-L2 represent an interactive self-learning tool designed to teach dimensioning criteria of mechanical features concerned to elementary machining processes [10]. TDLT-L2 is based on video and drawing animations, that links real machining processes with the dimensioning of the correspondent workpiece represented in technical drawings, see figure 3a.
a)
b)
Fig. 3. a) Screenshot sequence of the video of milling a keyway type A; b) a picture of the tablet application.
7
In particular, this tool was developed to improve the knowledge of which elements to measure, considering a manufacturing or technical point of view and, to provide students with greater awareness of the strong connection between machining operations and the design and drawing of the correspondent workpieces. For these reasons, TDLT-L2 tool is addressed to the students enrolled in the first years of courses in Mechanical and Management Engineering and it is implemented as a standalone application for PCs and tablets (Figure 3b). This tool allows students better understanding the implications of different machining processes on dimensioning of specific geometrical features of a mechanical object. This tool aims at improving the students’ abilities in TD and it is not a goal of this tool to be used for investigating the principles of machining or to explain the dynamics of those processes. Moreover, the focus of TDLT-L2 is to highlight the different steps of the machining processes performed on the workpiece without considering the particular kind of machine used (traditional, numerical control, or working center, …). This way, the videos and the animation of quite twenty elementary machining process, belonging to basic drilling, milling and turning operations, were realized [10]. To evaluate the effectiveness of the tool a preliminary validation test was conducted with some students of Udine University. First, students were asked to complete two dimensioning exercises using only the knowledge and competences acquired during previous lessons or their personal background. Only after the test, the new TDLT-L2 tool was presented and all the videos, of the different machining processes, were shown to the students. Then, the students were asked to repeat the two dimensioning exercises again trying to apply the concepts seen in the videos. The total marks obtained in the first run of the exercise (before videos) and in the second (after videos) were analyzed statistically using t-test. It can be seen that the average mark obtained after the videos was about 8.8% higher than the average mark obtained before and ttest results evidenced that this difference of the mean of the two populations was statistically significant at 95% confidence level. The t-test was also applied separately to evaluate the difference in behavior between the Management and the Mechanical Engineering students involved in the dimensioning exercises. The t-test was significant in the case of Management Engineering students but not in the case of Mechanical Engineering students probably due to their previous background of knowledge [10]. This way TDLT-L2 tool can be considered as a valuable aid for self-learning and for knowledge improvement of the students. For the following academic years, the authors would like to use the tool as a didactic aid for the students and as a support for the improvement of the TD lectures.
2.4. Other practices In each location there are also used other best teaching practices. In particular, at Brescia University an extended version of the online test with thirty questions,
8
is currently used as the written part of the final exam for TD courses. As a result , the data collected were also used for an extensive discussion, better described in [11], considering the influence of the a-priori knowledge of TD arguments, in function of students’ secondary school of origin, with their performance during the final examination. Another possible use of the online test, to be verified in the next period, is to use it as a standard placement test for TD. At Udine University, it was also introduced an entrance test, based on simply graphical questions to assess the level of knowledge of basic TD concepts such as axonometric and orthogonal projection and the sketching skills held by the students before attending the course .
3 Conclusions and future development In this paper, some examples of best practices in teaching, implemented, and regularly used in Brescia, Udine and Cassino Universities have been presented. These experiences were particularly interesting for both teachers and students that participated. The learning tools developed are performing well and the preliminary results of their use are encouraging, and some of them are already published. Currently, it is expected to maintain the collaboration between our three research groups, and to extend it to other interested partners. The preliminary results of these experiences may be used for the improvement of the quality of teaching and learning of different TD topics. The ongoing analysis of the data collected from the use of the online test tool shows the great interest and significant participation of students and consolidate the evolution of the learning activities from teachercentered to student-centered. Moreover, the evaluation of the effectiveness of these kind of tools will contribute to the improvement of the basic concepts belonging to the TDEG and to the development of new assessment and selfassessment tools to be used in basic TD courses. In addition, other initiatives aimed to improve the quality of teaching and the support to the study are currently under development.
References 1. Lemus‐Zúñiga LG, Montañana JM, Buendia‐García F, Poza‐Luján JL, Posadas‐Yagüe JL, Benlloch‐Dualde JV. Computer‐assisted method based on continuous feedback to improve the academic achievements of first‐year students on computer engineering. Computer Applications in Engineering Education. 2015, 23(4), 610-620. 2. Cerra, P.P., González, J.M.S., Parra, B.B., Ortiz, D.R. and Peñín, P.I.Á. Can Interactive Webbased CAD Tools Improve the Learning of Engineering Drawing? A Case Study. Journal of Science Education and Technology, 2014, 23(3), 398-411.
9 3. Carnegie Mellon University. Principles of teaching. www.cmu.edu/teaching/principles/teaching.html accessed 21/04/2016 4. Violante MG., Vezzetti E. Design of web‐based interactive 3D concept maps: A preliminary study for an engineering drawing course. Computer Applications in Engineering Education. 2015, 23(3), 403-411. 5. Metraglia R, Baronio G, Villa V. Learning Levels In Technical Drawing Education: Proposal For An Assessment Grid Based On The European Qualifications Framework (EQF). International Conference on Engineering Design, ICED 11, Vol. 8, Lyngby/Copenhagen, Denmark, August 2011, pp 161-172 6. MOODLE: https://moodle.org/?lang=it accessed 21/04/2016 7. CINECA: http://www.cineca.it/it/content/e-learning accessed 21/04/2016 8. Barr, R. E. The current status of graphical communication in engineering education, Frontiers in Education, FIE 2004, Vol. 3. Savannah, GA, October 2004, pp. S1D/8- 8. Barr, R., "Engineering Graphics Educational Outcomes for the Global Engineer: An Update," Engineering Design Graphics Journal, Vol. 76, (2012), 3, pp. 8-12 9. Barr, R. Engineering Graphics Educational Outcomes for the Global Engineer: An Update. Engineering Design Graphics Journal, 2012, 76(3), 8-12 10. Baronio, G. Motyl, B. Paderno, D. Technical Drawing Learning Tool-Level 2: An interactive self-learning tool for teaching manufacturing dimensioning. Computer Applications in Engineering Education. DOI - 10.1002/cae.21728 11. Metraglia, R. Villa, V., Baronio, G. and Adamini, R. High school graphics experience influencing the self-efficacy of first-year engineering students in an introductory engineering graphics course. Engineering Design Graphics Journal, 2015, 79(3)
To cite this document: SPERANZA, D., BARONIO, G., MOTYL, B., FILIPPI, S., & VILLA, V. (2017). Best practices in teaching technical drawing: experiences of collaboration in three Italian Universities. In Lecture Notes in Mechanical Engineering - Advances on Mechanics, Design Engineering and Manufacturing (pp. 903913). Springer International Publishing. ISBN 978-3-319-45781-9, doi 10.1007/978-3-319-45781-9_90, http://dx.doi.org/10.1007/978-3-319-457819_90
