Development of a Crystal Spatial Visualization Survey for Introductory Materials Classes

Stephen Krause, Alexander Sterling, Jacquelyn Kelly, Danny Stehlik, Omowunmi Isaacs-Sodeye, Dale Baker
2012 ASEE Annual Conference & Exposition Proceedings   unpublished
Spatial visualization ability is a key skill for engineering students and practitioners in many engineering disciplines. In material science and engineering, it is a critical skill for understanding and modeling relationships between materials structure at the microscopic structural level and the macroscopic property level. An important microstructural feature of materials is their crystal structure, which plays an important role in determining some of a material's macroscopic properties, such
more » ... s yield and tensile strength. As such, it is quite useful to be able to visualize two-dimensional projections of atom locations on different planes for a given crystal structure for which deformation mechanisms in metals can be described with simple sketches of planar atomic packing diagrams. However, this critical spatial visualization skill is also difficult for some students to learn, understand, and use. Thus, the research question for this paper is, "What are students' misconceptions and prior knowledge associated with drawing 2-D images of hard sphere atom models of planar packing for different metal structures and how can they be characterized". Answering this question should provide knowledge and insight about student learning issues with potential for developing more effective pedagogy for teaching and learning about crystallography of materials' structures. To uncover prior knowledge and misconceptions, students from 4 semesters of materials classes were given worksheets prior to instruction and asked to sketch planar packing images of (100), (110), and (111) planes for simple cubic, face centered cubic, and body centered cubic crystal structures. The sketched images were analyzed and revealed a number of characteristic misconceptions that included: missing atoms, extra atoms, misplaced atoms, non-touching atoms, and touching atoms. Other misconceptions were also present but with much lower frequencies of occurrence. After instruction, the frequency of misconceptions was much reduced and the most frequent types of misconceptions had also changed. From these results, a 10-item, multiple choice, Crystal Spatial Visualization Survey was created. The survey was given as a pre-post test during the Spring 2012 term of a materials course and reproduced reasonably well the results of the earlier hand-sketched results of a similar visualization test. Additional testing with more students in other settings will be needed to verify the reliability of the Crystal Spatial Visualization Survey. As such, it is a preliminary instrument that has good potential as a crystal structure pretest for being a quick and reliable method to test students baseline ability of visualizing 2-D projections as well as a post-test to measure the effectiveness of instruction on understanding and visualization ability of students for crystal structures. Issues about student understanding and instruction are discussed in the paper.
doi:10.18260/1-2--21207 fatcat:7jzuccxgangvjffqxooq4hczry