Teaching linear circuit analysis techniques with computers

We describe recent progress in the development of a step-based computer-based tutoring system to aid in the teaching of introductory linear circuit analysis courses, and preliminary assessment of its effect on student learning in a controlled trial. The system is based on a software engine that can generate problems with random circuit topologies of specified characteristics as well as full solutions performed using techniques typically taught in introductory classes. A graphical circuit editor, an equation entry system using pre-defined templates for each term, a simplified algebraic and matrix equation entry system have been implemented to accept and evaluate a wide variety of student inputs, rather than just numerical answers. Pedagogical features such as color coding and labeling of specific currents and voltages have been implemented to clarify the origin of node and mesh equations describing a circuit. Tutorials have been developed covering identification of series and parallel circuit elements, and writing of node and mesh equations. A laboratory-based evaluation of two of these tutorials using paid student volunteers showed that they are about 10X as effective as conventional textbook exercises in promoting student learning of these topics when used for the same period of time, with a statistically significant difference. The effect size of the tutorial usage is found to be 1.21 pooled standard deviations (i.e., a Cohen d-value of 1.21). This type of system is therefore expected to be a great improvement over conventional homework, when fully implemented.