The purpose of this assessment probe is to elicit students’ ideas about complete circuits. It is designed to reveal how students think current flows in a circuit. The probe is best used with students in grades 3–8. Make sure students are familiar with how a switch operates and that they can distinguish between the two different configurations shown on 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.