Kirchhoff's Pen

Abstract

Kirchhoff's Pen is a pen-based tutoring system that teaches students to apply Kirchhoff's voltage law (KVL) and current law (KCL). To use the system, the student sketches a circuit schematic and annotates it to indicate component labels, mesh currents, and nodal voltages. The student then selects either mesh (KVL) or nodal (KCL) analysis, and writes the appropriate equations. The system interprets the equations, compares them to the correct equations (which are automatically derived from the circuit), and provides tutorial feedback about errors. Unlike traditional tutoring systems that work from input provided with a keyboard and mouse, our system works from ambiguous, hand-drawn input. The goal of our work is to create computational techniques to enable natural, pen-based tutoring systems that scaffold students in solving problems in the same way they would ordinarily solve them with paper and pencil. Kirchhoff's Pen is an important first step toward this goal.