Students' Mental Models of Electricity in Simple DC Circuits
This study presents the results of research into middle school students’ knowledge about the nature and mechanisms of action of electricity in simple DC circuits. Sixth, seventh, and eighth graders (n=99) were asked a series of questions about the roles of bulbs, batteries, wires, and electricity in circuits. Almost half the number of students (n=42) were found to have used detailed, well-defined, and logically consistent mental models based on their responses. A total of 15 different detailed mental models were documented in these students that belonged to one of four different general model types: (I) round trip flow using both ends of the battery, (2) round trip flow using one end of the battery, (3) one way flow using both ends of the battery, and (4) one way flow using one end of the battery. These models were composed of eight different components that each represented the students’ conceptions of different parts or aspects of the circuit. A majority of the students (n=75) were found to have used one of the general model types, 22 used more than one general model types, and 2 were categorized as undetermined as to whether they used any or no general model type at all. A theoretical framework is outlined which explains the formation of initial, synthetic, and scientific models and how this study informs that framework. The relationship between mental models and conceptions and how it relates to this study is also discussed.