In-class and recorded physical demonstrations in enhancing student understanding of structural mechanics courses

Abstract

BACKGROUND One of the main challenges educators face when teaching structural mechanics courses is the difficulty for students to visualise the relation between the concepts taught and the actual physical meaning on the behaviour of materials or actual structures. Not visualising the structure's responses to loads may not support learning as it can lead to false interpretations of the actual structural behaviour. If the concepts taught do not appear "real" to students, then mechanics courses are merely exercises with mathematics and equations with no connection to any practical significance. Physical models (demonstrations aids) have been developed and extensively used at Griffith University in the last several years as a tool to convey fundamental structural mechanics concepts. The approach has been highly valued by all students who unanimously claimed that the demonstrations greatly helped their overall understanding of the courses. However, when comparing students' performance before and after the use of the demonstrations, or when testing students on concepts taught with and without the use of demonstrations, no clear quantitative evidence was collected in the past on the actual effectiveness of these teaching tools. Prior to Semester 1, 2013, the models were only demonstrated during lectures. The authors believe that students at the back of the lecture theatre may not have been able to clearly see the demonstrations performed by the lecturer in the front of the class. This may not have had assisted their understanding. Moreover, while some concepts may be obvious to the students while being demonstrated, students may need more time to assimilate and review the concepts at their own pace. From Semester 1, 2013, a video camera was introduced to project the demonstrations on the lecture theatre screen, therefore reaching the entire audience. From Semester 2, 2013, videos were also recorded and uploaded on the course sites for students to review the concepts in their own time. PURPOSE The purpose of this study is to collect evidence on the effectiveness of (i) using physical demonstrations in class, (iii) projecting these demonstrations on the lecture theatre screen and (iii) posting recorded videos of the same on the course website, on students' overall understanding of fundamental structural mechanics concepts. APPROACH A total of 216 students, from three structural and mechanics courses offered in Semester 2, 2013, were surveyed on the effectiveness of using physical demonstrations (in-class) and recorded demonstrations (outside class) on their understanding of fundamental structural mechanics concepts. RESULTS AND CONCLUSIONS Results showed that the use of physical models in-class is an efficient technique to convey complicated structural mechanics concepts. In large classes, the use of the video camera to project the demonstrations on the lecture theatre screen was also shown to be effective in reaching the entire audience. Additionally, the use of videos of the demonstrations placed on the course website was shown to help students in further mastering and reinforcing the important concepts taught. Results suggest that the videos are useful for about half of the students, as the in-class demonstrations would be sufficient for the other half to grasp the concepts taught.