Abstract: It has come to the attention of physics instructors that the engineering students enrolled in Malaysian universities do not possess sound conceptual understanding in basic electricity. Preconceptions and misconceptions regarding this subject matter especially on the topic of parallel resistors have been seen to exist amongst aspiring engineering degree students. Ironically, to date there are not many effective measures taken to arrest this issue. In addition, the existence of appropriate instruments within the local mainstream to measure these students conceptual understanding of the related topic of parallel resistors is insufficient. Among the few claimed instrument was designed by Beh has been used to assess the students conceptual understanding which has revealed some significant findings and led to some suggestions for the improvement of the current electricity syllabus and teaching instructional methods. However, recent developments within the Malaysian Institution of Higher Learning in science education system, call for a re-validation and improved measurement instrument. The aim of this research is to investigate the validity of this instrument, PCCUT_40-Parallel Resistive Circuit test using Rasch analysis in measuring the conceptual understanding of engineering students in institutions of higher learning in Malaysia on the topic of parallel resistors. The methods used are by purposive sampling on recently enrolled engineering students. The instrument focused on the six main domains which are the meaning of parallel, practical knowledge of current, voltage, resistance, followed by circuit connection and finally the mental model. Data collected were analyzed using WINSTEPS version 220.127.116.11. The result shows that the instrument has excellent item reliability of 0.94 logit, SE 0.33 and good item separation of 3.82 logit, SE 0.30. Quality control procedures have resulted in an item reduction from 40 to only 28 items, thereby producing a better instrument in measuring the students conceptual understanding of parallel resistors, the new PCCUT_28.
A.A. Azrilah, A. Nazlinda, M. Mohd Saidfudin and A. Zaharim, 2013. Investigation of Parallel Resistive Circuit PCUT-40 Instrument Construct Validity to Assess Engineering Students understanding in Electricity. Research Journal of Applied Sciences, 8: 470-476.