Defining precise measurements with sketched annotations

Technology has been largely employed in the modern education system but rarely fosters natural communication between the human and the machine. We wish to explore the use of sketch recognition based software as a medium for student computer interaction within the context of computer assisted tutoring systems. Since the student can draw directly on the screen in this scenario, the interaction mimics familiar pencil and paper techniques while the speed and one-on-one attention of the computer alleviate some of the challenges currently faced by students and teachers in a traditional education setting. Furthermore, we wish to promote the incorporation of more free response questions ("build a structure to meet these requirements" instead of "analyze this structure") into the modern curriculum. These types of questions are rare because of how difficult they are to grade, but more closely approximate reality and provide context for the methodologies learned in the classroom. Free response questions require a large degree of flexibility and an overall more intelligent tutoring system than has been previously studied. Mechanix is a sketch recognition based tutoring system that provides immediate feedback for engineering statics problems. In order to extend Mechanix to support free response problems, the software needs to know the precise physical properties of sketched elements. We introduce measurement mechanisms such that, with minimal effort, a user may specify the precise measurements of a truss, so that Mechanix can create and solve systems of equations to determine how forces are distributed throughout the truss. Therefore, given a sketched truss and measurements as a response to a free response questions, the system may determine whether the structure satisfies the requirements of the question.