This research-based student tutorial covers superposition and symmetry in electrostatics. The material is appropriate for a calculus-based introductory physics course.

The tutorial is designed for use after traditional instruction as an in-class supplement, out-of-class homework, or student self-study tool. The authors recommend that the tutorial be given in-class to students working in groups of 2-3. A majority of student groups can finish the pre-test and tutorial in a 1 hour 50 minute period.

A pre-test and post-test are available to assess student learning. If used, the pre-test should be given after traditional instruction and before the tutorial. The post-test should be given the following class so that students that do not finish the tutorial can do so at home before taking the post-test. The pre- and post-tests each require 15-20 minutes to complete. Professors may choose to give the pre-test in-class after traditional instruction, the tutorial as homework, and the post-test in the following class.

This work is based on research into students' common difficulties in learning the superposition principle and symmetry in electrostatics. Some findings are available in Student Understanding of Symmetry and Gauss's Law of Electricity, Am. J. Phys. 74 (10), 923-936 (2006). Details of the design, construction and testing of the tutorial are available in J. Li, Improving Students' Understanding of Electricity and Magnetism, Ph.D. Dissertation, University of Pittsburgh (2012) and J. Li and C. Singh, Investigating and improving introductory physics students' understanding of electric field and the superposition principle: The case of a continuous charge distribution, Phys. Rev. PER 15, 010116 (2019).