Mechanix: The Development of a Sketch Recognition Truss Tutoring System

TLDR: In this article, a sketch recognition tool for engineering students to learn how to draw truss free-body diagrams (FBDs) and solve truss problems is presented. Mechanix is able to provide immediate and intelligent feedback to the students; it tells them if they are missing any components of the FBD, and it can also tell students whether their solved reaction forces or member forces are correct or not without actually providing the answers.

Abstract: Mechanix is a sketch recognition tool that provides an efficient means for engineering students to learn how to draw truss free-body diagrams (FBDs) and solve truss problems. The system allows for students to sketch these FBDs, as they normally would by hand, into a tablet computer; a mouse can also be used for regular computer monitors. Mechanix is able to provide immediate and intelligent feedback to the students; it tells them if they are missing any components of the FBD. The program is also able to tell students whether their solved reaction forces or member forces are correct or not without actually providing the answers. Mechanix also has a checklist feature which appears in the same window as the program, it guides the students through the problem and automatically updates as the student progresses and solves each part of the truss problem. This paper presents a study to evaluate the effectiveness and advantages of using Mechanix in the classroom as a supplement to traditional teaching and learning methods. Freshman engineering classes were recruited for this experiment and were divided into an experimental group (students who used Mechanix in class and for their assignments) and a control group (students who were not exposed to Mechanix). The learning gains between these two groups were evaluated using a series of quantitative formal assessments which include concept inventories and homework, quiz, and exam grades. Qualitative data was also collected through focus groups for both groups to gather the students’ impressions of the programs for the experimental group and general teaching styles for the control group. Due to some issues with the server that runs Mechanix, the students were not able to properly use Mechanix during the in-class evaluations. We believe that this caused the results to show that there was no change in the homework and concept inventory scores between both groups for the current evaluation. However, the results show that Mechanix is a capable tool for enhancing students learning and performance in exams. The focus group discussion showed that the students really liked the program; they mostly appreciated the instant feedback and they said that Mechanix motivated them to move on to more problems when they saw that they had successfully solved the previous ones.