Mechanix: A Sketch-Based Tutoring and Grading System for Free-Body Diagrams

Mechanix is a tutoring and homework system aimed specifically at support free-body diagrams for both students and instructors. Due to the increasing size of introductory-level physics, mechanical and civil engineering courses, the ability for an instructor to provide useful and timely feedback to students on free-body diagrams is becoming increasingly more difficult. Mechanix automates most of the process of comparison and saving information from students and instructors via extensive use of geometric recognition. The student is asked to draw free-response solutions on in an area, where the points that comprise each stroke are then analyzed for different patterns. These patterns include rule sets that make up most basic geometric shapes, such as triangles, circles, squares, and lines of varying length and angle. These are then compared against other immediately adjacent points to determine whether this shape is part of a larger, more complex one. For instance, the letter "X" has two strokes of varying points each. First, the system determines that the line of points comprises one of the two strokes (recognizing the line " / "), and the ladder-based system then recognizes the other (" \ "). The system then detects that the two lines are intersecting in the midpoint, thus Mechanix recognizes "X" to be drawn. This same concept is carried over to all the other shapes that Mechanix recognizes, including complex trusses. The system then uses the input provided by the instructor to determine if the students' answers match those of the instructor via the same concepts of geometric recognition. Piecemeal feedback is given to students to help guide them to the correct answer without too many or too few hints. Mechanix uses a centralized server system to perform sketch recognition on answers as well as prevent students from cheating by not saving the instructors' answers locally.

I believe Mechanix's true potential is in the fact that it can be expanded to a very large variety of domains of education. It can even be used without much work in a language learning environment, where a student can learn Japanese Kanji or Arabic writing with the system able to provide useful feedback on the correct use and composition of particular characters. Additionally, the system provides ample room for other students to generate a particular sort of crowd-sourcing element to the learning experience, where a limited version of the instructor mode could be made available to students to quiz each other and further provide tutoring options. One of the potential drawbacks of the system, however, is that the instructor input will be useful only in the context of Mechanix. A system could be made to easily export or import data into or out of Mechanix to let instructors use the questions they write to be used in written materials, exams, or other classes that do not integrate Mechanix into the classroom.