Incorporating Active Learning of Complex Shapes in STEM Courses

A major obstacle students encounter in many STEM subjects is visualization of complex threedimensional shapes, such as the p-v-T surface in thermodynamics. Conventional means of content delivery, such as textbooks and projector screens, are passive in nature and are ineffective in many situations. Alternatives such as immersive visualization technology are often costly and require specialized laboratory, creating a disconnect between lecture and spatial learning. An exploratory method is introduced whereby learners can achieve meaningful, longterm understanding of the material by constructing 3-D objects. This method was implemented in a thermodynamics course over two consecutive semesters at University of Illinois at Chicago. Overall, the observations suggest that the proposed method can yield a significant improvement in student learning of the subject. Introduction The current mechanical engineering curriculum at University of Illinois at Chicago (UIC) includes introductory and intermediate thermodynamics courses. In the introductory course, instructors primarily use traditional lecturing method, supplemented by an in-class display of a plastic mold of the p-v-T surface – the first examples of which were constructed by James Thomson1 in 1871 and James Maxwell2 in 1874. Despite the sculpture display, however, a significant number of students who subsequently enrolled in the intermediate thermodynamics course, instructed by the author, struggled to make sense of the p-v-T surface and failed to use the data tables for calculations. Many students in the intermediate thermodynamics class often made the mistake of constructing improperly sloped isobars on a T-v diagram (or isotherms on a p-v diagram). Consequently, using the data tables to identify the state of a substance became challenging, and errors were made as a result. More complex problems involving the first and second laws, as well as cycle analyses, presented an even bigger obstacle, and it all stemmed from the lack of, or incorrect, understanding of the p-v-T surface. This paper intends to introduce a method of rectifying the problem and enhancing student success in thermodynamics. The same method may also be applied to other core STEM courses where complex shapes are the fundamentals for understanding the subject matter. Many STEM subjects are three dimensions in nature. From human anatomy to particle transport, complex geometries are involved. A major obstacle students encounter in these courses is visualizing these three-dimensional shapes, such as the p-v-T surface in thermodynamics. Often times, understanding of the subject matter cannot be achieved without a firm and thorough appreciation of the intricacies in the geometry. Conventional lecturing methods, such as textbooks and projector screens, are passive and twodimension in nature, and are ineffective in many situations. In recent years, many attempts have P ge 26938.2 been made whereby the conventional methods are challenged. Programs such as NSF's Engage3 and pedagogies such as classroom flipping4 are being demonstrated across many institutions. However, these strategies may present an adoption-rate challenge among instructors, particularly seasoned professors and lecturers who may have already developed structured lesson plans that are resistant to modifications. Other alternatives such as immersive visualization technology are often costly and require specialized laboratory and wearable equipment, creating a disconnect between lecture and spatial learning. The positive impact of active learning, spatial visualization and tactile models in long-term student success has been well documented. Clark and Jorde5 described a sensory instrument to help science students achieve a deeper understanding of thermal equilibrium. Dewoolkar et al.6 incorporated inquiryand team-based learning in geotechnical engineering courses and saw promising results in student outcome. An active learning strategy was proposed and successfully implemented by Hall et al.7 McGrath and Brown8 described the importance of visual technique in STEM courses. Bullard and Felder9,10 documented the many benefits of active learning in young adults and STEM students alike. Prince11 dissected the effectiveness of active learning and showed its impact in student outcome. Dong12 documented the importance of spatial learning skills in STEM subjects. An exploratory method is introduced whereby the teaching of thermodynamics fundamentals is accomplished through student-centered and team-based active learning, spatial visualization and tactile modeling. With this method, learners can achieve meaningful, long-term understanding of the material by constructing 3-D objects – a p-v-T surface, in this case. This method may also be implemented in many core STEM courses without the need for restructuring, and without incurring additional cost. Learners assume the role of information creator instead of audience. Using existing material or technology – free or open-source software, foodstuffs, etc. – students now build the object from the ground up, by imitation, imagination, or both. The deliverables include a computer model as well as physical product, and the desired outcome is a meaningful appreciation of the 3-D object of interest and, ultimately, the subject matter. Methodology and Goals The primary learning goals are for students to achieve a long-term understanding of the p-v-T surface, and how to use data tables in practical calculations. The secondary goals include an appreciation of complex geometry, acquiring new software skills, and collaborating effectively with peers to produce results. The goals for administration (i.e., faculty, department or institution) are to incur minimal cost, and be able to implement the method in existing courses with relative ease and without having to overhaul the curriculum. The approach presented herein consists of two parts: tactile and software. In part one, students are tasked with sculpting a p-v-T surface using any foodstuffs and bringing the completed sculpture to the following class. In part two, a CAD model is to be created and subsequently imported into a freely-available scientific visualization tool, with the best submitted model selected for 3-D printing. Figure 1 below illustrates the process. It begins with adjusting the grading scale to accommodate P ge 26938.3 the projects. For this project-based approach to succeed, the course syllabus must be modified by the instructor such that the project weighs substantially in determining the student's overall grade. An example of the old and new grade scale is shown in Table 1. Figure 1. The process. Table 1. Revised grading scale. Old Grading Scale (%) New Grading Scale (%) Projects 10 40 Homework 10 0 Quizzes 10 20 Midterm Exam 40 20 Final Exam 30 20 P ge 26938.4 Part One: Sculpting with Foodstuffs This portion of the project may be considered a “pre-project.” It is designed to incite a sense of fun, encourage participation, and engage in initial learning. For this project, due the next class, each student individually is tasked to create a tangible p-v-T surface by sculpting foodstuffs. To minimize waste and cost, students are encouraged to use their planned meals. Once completed, students must either bring the food sculpture to the next class, or present photographic evidence by the same deadline. Part Two: CAD and Paraview Project Part two is the focus of the approach, and it is a team-based project due in four to six weeks. Teams of three to four students are formed by random assignment. Each team member's agreedupon task(s) must be clearly defined and well documented in a group report that accompanies the final deliverables. Each team must create a 3-D CAD model of the p-v-T surface in any CAD software package that is royalty-free for the public, open source, or commercially available with free student license. Packages from AutoDesk, for example, have been made available for all students without cost, while TurboCAD offers free trial period, and Google SketchUp is freely available to the public. Specialized commercial software such as SolidWorks and Creo are also allowed if it has already been installed on campus computers, so that no additional licensing cost will be incurred. Proficiency in using CAD software is essential for STEM students. In a typical engineering curriculum, students usually acquire CAD skills during the first two or three semesters. Therefore, most students enrolled in core STEM courses are expected to possess at least rudimentary level of CAD proficiency. For those without any or much experience in CAD, however, this portion of the project can serve as a peer-learning opportunity. In constructing the 3-D model, students are in complete control of every detail of the surface and the degree of accuracy. Once created, the CAD model is then visualized by importing it into Paraview. Paraview is a powerful, open-source software for visualizing multidimensional scientific data. It is widely used in the scientific and engineering research community as well as commercially. In Paraview, students can manipulate the model by slicing it in multiple axes, whereby isobars (in T-v orientation) and isotherms (in p-v orientation) are created and superimposed on the 3-D surface. Alternatives to Paraview include K3DSurf, Misfit Model 3D, Houdini, among others. Paraview is chosen as the visualization software of choice because it has been identified by the author as the most popular across industries, and it has a strong online support community. All submitted models are subsequently judged by the instructor. A score, up to 100%, is assigned to each team based on the quality of the 3-D model and the report. The submitted model that best resembles a p-v-T surface is handpicked for 3-D printing, and the printed parts are in turn presented to the entire class. Page 26938.5