Observations provide evidence of a chemical change. The purpose of this assessment probe is to elicit students’ ideas about chemical change. The probe is designed to find out what changes students use as evidence of a chemical change. It is best used with students in grades 3–12, and should be modified for grades 3–5 by eliminating answer choices that are not familiar to the students. The probe can be used with the card sort or claims card strategy and can be extended using the always, sometimes, and never formative assessment technique. The probe is provided in English and Spanish. A materials list, teacher notes, standards, assessment, and references are provided. This book selection also includes the Table of Contents, Preface, Acknowledgments, Dedication, About the Authors, Introduction, and Index.