The purpose of this probe is to elicit student ideas about magnetic poles. The probe is designed to reveal whether students think a magnetic field must always have magnetic poles. It is best used with high school students. If materials are available, consider modeling the probe scenario with a compass. 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.