Improvements in student spatial visualization in an introductory engineering graphics course using open ended design projects supported by 3 D printed manipulatives

This work in progress reports changes in development of Spatial Visualization (SV) skills in students taking a first semester Engineering Design Graphics course modified to integrate geometric design modules supported by manipulative production through 3D printing. The ability to imagine three dimensional objects, to visualize them in rotated states, and to subsequently communicate them in 2D (sketches) and 3D space (virtual solid models) is a critical skill for engineers, and a large body of research has shown that the development of these skills is indicative of student success and persistence in engineering. Thus a course that due to its non mathematical nature is often perceived as non critical, in practice has demonstrated to be of high importance, as it is where decisions for exiting the program are made. The improvement of the development of SV skills during the freshman year has also received significant attention in the literature. The widespread teaching of 3D solid modeling software for the past two decades has introduced the capability to easily visualize objects in three dimensions, and typically constitutes the core content of the first design course. The flipside of this development is that the learning curve for the normally employed parametric solid modeling software is steep, and requires explicit instruction on the use of the software. Thus the course often has a focus on learning the software (which is typically done by requiring the students to learn the software by modeling existing 2D or 3D representations of an object) and not a design focus, where students develop a geometric solution to a stated problem without having any prior representation of the solution. The latter clearly requires the students to visualize the geometry of a solution before it is generated (either on paper or virtually in the computer) The work in progress presented here assesses differences in SV development in students enrolled in two sections of the same Engineering Graphics and Design course during the Fall 2015 semester; one that is taught in the traditional fashion and that represents a control group of 80 students, and a second section (76 students) modified to include two week long and appropriately scaffolded geometric design exercises. Part visualization is supported by requiring the students to use and/or print 3D manipulatives of the parts that constitute the connecting elements to their freeform design problem, and to generate prototypes of their final solution in order to test assembly capability. The assessment tool utilized is the Purdue Spatial Visualization Test Rotations, administered in pre and post mode in both sections.  The ability to process visual information and the ability to create mental images of two dimensional representations of existing objects are critical skills for engineering students, as solutions to analytical engineering problems as well as the ideation process in design require spatial visualization (SV) skills. All sighted individuals have the ability to process visual information; however, not everyone can inherently process visual information at the same level or speed. Cognitive training is required not only to process visual information faster but also to enhance SV ability. Based on differing levels of innate ability, prior training and experience, engineering students enter the first semester with greatly varying levels of SV aptitude, with many first year engineering students not having developed the visual analysis and synthesis skills needed in engineering (visual analysis is the ability to see objects and express them through graphical representations, while visual synthesis is the ability to imagine or create a mental image of an object and express then through graphical representations) This problem has been widely reported and addressed in prior work and numerous strategies have been explored. The advent of 3D solid modeling over the past three decades has supported this development by introducing an easy way to virtually visualize objects in three dimensions. As a result, industry and engineering programs have embraced this technology, and now learning an industry typical CAD software package typically represents the backbone of the first design course. The flipside of this development is that the learning curve for modern parametric solid modeling software is steep, and requires explicit instruction on the use of the software. Thus typical first year Engineering Design Graphics courses typically focus on teaching a specific CAD software package, and do not specifically address the development of students SV skills and self regulation, which are direct indicators of student academic success and persistence in STEM. The research presented here specifically targets the development of SV skills by designing and implementing geometric design modules supported by the creation and use of 3D manipulatives.  Synopsis of literature The importance of SV has received much attention over the past years. Already in 1955, the Grinter Report 10 outlined a vision of engineering education that clearly addresses the necessity of developing SV skills, this report was followed by numerous studies have reiterated the importance of SV skills and their link to success in the technical disciplines. The assessment of SV skills builds primarily on the seminal work of Shepard and Meltzer that has resulted in the Mental rotations Test (MRT) and Guay's Purdue Spatial visualization Test Rotations (PSVT:R) Their work has created the foundation of a range of tests that have been developed over the past decades. Typically SV tests rely on students interpreting the graphical representation of 3D objects, and identifying which of the graphical representations given corresponds to the reoriented object. The PSVT:R used here introduces rotations about one, two and three axes, which are presented in increasingly difficult increments. Students need to identify the correct rotated representation in a multiple choice environment within a limited time window. Not only is SV an important skill for engineers, but it is also linked to academic success. Recent studies, such as the one conducted by Lubinski in 2010, relate success and persistence in the STEM fields to high levels in SV at the adolescent age: ".the consistently distinguished levels of spatial ability among adolescents who subsequently go onto earn STEM educational degrees and occupations, relative to adolescents who secure educational credentials and occupations in other areas, reveals the importance of spatial ability in STEM arenas." (Lubinski, 2010) A number of secondary and tertiary level studies 3, 9, 2, 5, 13 clearly ratify this development by observing the SV development in first year engineering students. Moreover, this clear research based link between high SV skills and academic success has also unveiled a gender gap, showing a widely reported male advantage over females in the results of the SV tests 14, 15, 16, 17, 18, This male advantage can have detrimental effects: "Design Graphics courses are among the first courses in which first year engineering students enroll. For this reason, students who have poorly developed spatial skills, particularly women, may become discourage and drop out of engineering altogether if they are struggling in their first engineering course while their classmates seemingly breeze through the material." (Sorby, 2009 It is critical to address SV skills early in the professional formation of engineers to not only ensure adequate technical skill acquisition, but also to address this gender gap in order to support increased female persistence in engineering programs. Sorby 2, 3, 5, 19 has investigated and implemented a number of interventions to help students overcome SV deficiencies by proposing increased hand sketching, creating shapes from paper cutouts, as well as having online visualization modules. Results indicate improvements in SV for students that undergo these remedial measures. Sorby concludes that courses that "stressed hands on sketching and drawing tended to improve spatial skills more than those courses that stress computer aided design methods" In contrast, Connolly et al 21 report that the remedial SV modules (workbook and CD, but no physical manipulatives) developed and applied in the context of a mutli institution collaboration show no statistically significant improvement. To date, explicitly addressing the development of SV skills in first year engineering students has been focused on these activities that favor students' creative graphical expression over focused software learning. With regard to manipulatives and gestures supporting the development of SV skills, significant work has been done Chu and Kita 22, who have addressed the beneficial aspects of gestures in spatial problem solving, and investigated changes that occur over time as the subjects develop proficiency in SV. Their results show that while the gesture and manipulation motor strategy becomes increasingly internal and decoupled from the physical agent as proficiency increases the use of a motor strategy does indeed support the development of SV Study 24 carried out an extensive analysis on the relationship between and assessment of haptic and visual abilities in freshman engineering students, concluding that there are indications that visual and haptic abilities are not mutually exclusive. Three dimensional manipulatives have been used in instruction in a number of disciplines to support the visualization of objects, such as anatomy to quickly produce adequate wind tunnel testing models in aeronautical engineering and as learning tools in undergraduate Mechanics courses 27, In addition, manipulatives have received attention in secondary education, both in teacher and student education 29, 30, 31, However, there has been little systematic use of 3D pr