Examining students' understanding of electrical circuits through multiple-choice testing and interviews
Research has shown that both high school and university students have misconceptions about direct current resistive electric circuits. At present, there are no standard diagnostic examinations in electric circuits. Such an instrument would be useful in determining what conceptual problems students have either before or after instruction. The information provided by the exam can be used by classroom instructors to evaluate their instructional methods and the progress and conceptual problems of their students. It can be used to evaluate curricular packages and/or other supplemental materials for their effectiveness in overcoming students' conceptual difficulties.
Two versions of a diagnostic instrument known as Determining and Interpreting Resistive Electric circuits Concepts Tests (DIRECT) were developed, each consisting of 29 questions. DIRECT was administered to groups of high school and university students in the United States, Canada and Germany. The students had completed their study of electrostatics and direct current electric circuits prior to taking the exam.
Individual interviews were conducted after the administration of version 1.0 to determine how students were interpreting the questions and to uncover their reasoning behind their selections. The analyses indicate that students, especially females, tend to hold multiple misconceptions, even after instruction. The idea that the battery is a constant source of current was used most often in answering the questions. Although students tend to use different misconceptions for each question presented, they do use misconceptions associated with the global objective of the question. Students' definitions of terms used on the exam and their misconceptions were examined. Students tended to confuse terms, especially current. They assigned the properties of current to voltage and/or resistance.
One of the major findings from the study was that students were able to translate easily from a "realistic" representation of a circuit to the corresponding schematic diagram. Results indicated that students do not have a clear understanding of the underlying mechanisms of electric circuit phenomena. Students had difficulty handling simultaneous changes of variable. Current was the main concept used in solving the problems. Some of the students who were interviewed reverted to formulas to answer the questions.
0288: Educational evaluation
0533: Secondary education
0745: Higher education