The purpose of this assessment probe is to elicit students’ ideas about complete circuits and the structure of a lightbulb. It is designed to reveal how students think a battery and bulb need to be connected in order to complete a circuit. The probe is best used with elementary and middle school students. It may be helpful to show them an actual battery, wires, and bulb before responding to the probe. A materials list, teacher notes, standards, assessment, safety notes, and references are provided. This book selection also includes the Table of Contents, Preface, Acknowledgments, About the Authors, Introduction, and Index.