The purpose of this assessment probe is to elicit students’ ideas about electricity. It is designed to reveal students’ ideas about how current leaves a wall socket. The probe is best used with middle and high school students. Point to an outlet and a switch so students know what the probe is referring to. This probe can be extended by having students draw a picture to explain what they think is happening. 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.