Investigating the Relationship Between Student Difficulties with the Concept of Electric Potential and the Concept of Rate of Change

Abstract

An important aspect of curricula development is not only understanding what difficulties students have but also, why they have these difficulties. The purpose of this study was to investigate the possibility that students have difficulty with the concept of electric potential because they have difficulty with the concept of rate of change. The study sample consisted of over 300 students from various colleges and universities.

To investigate this relationship, I created a diagnostic instrument that contains 14 items on rate of change and 11 items on electric potential this is the Rate And Potential Test (RAPT). These items were taken from other diagnostic instruments or modified from questions used in other research studies. I also conducted think-aloud interviews to insure that students were interpreting the items correctly.

My findings can be broken into two areas. The first area deals with findings about the relationship between student difficulties with rate of change and electric potential. The second area of findings deals with the appropriateness of the RAPT for investigating this relationship. I found that there is a correlation between the way students answer rate of change items and the way they answer electric potential items. I also found that some students in upper-level undergraduate courses made mistakes similar to introductory students. The RAPT was found to be a reliable (KR20 = 0.83) instrument and it did not matter if it was given on paper or via WebAssign, a web-based homework delivery system.