摘要:AbstractThe concern of academicians regarding the understanding achieved upon instruction of electricity has given rise to the development of various instruments. Even though there are many studies on misconceptions in electricity, very few have used diagnostic instruments in identifying the students “strength and weaknesses including profiling them according to their ability. The aim of this paper is to investigate the validity of the instrument,Parallel Resistive Conceptual Understanding Test (PCCUT)using Rasch Analysis in measuring the conceptual understanding of engineering students on the topic of parallel resistors, including exploring the possibility of profiling them according to their understanding. The methods used are by purposive sampling on 102 students, consisting of 55% (56) majoring in Electrical Engineering, 27% (28) in Mechanical Engineering and 18% (18) in Civil Engineering. The instrument focused on the six main domains which are “the meaning of parallel”, practical knowledge of “current”, “voltage”, “resistance”, “circuit connection” and “mental model”. Data collected were analyzed using WINSTEPS version 3.71.0.1. The result shows that the valid instrument has “excellent” item reliability of 0.97 logit and “good” item separation of +5.37 logit (ítem strata of 7.49).