The purpose of this assessment probe is to elicit students’ ideas about precipitation. It is designed to determine whether students understand what causes the water in clouds to fall as rain. Elementary students’ emphasis should be on observing and describing weather, including rain events. Middle school students expand their experiences in observing and describing rain clouds to more conceptual ideas about the water cycle, including the composition and formation of rain clouds and the mechanism of precipitation. High school students use their knowledge of physics- and chemistry-related concepts to explain weather phenomena in the Earth system, such as rain. Their understanding of the water cycle is set into the larger context of matter cycling through Earth as a system. Teacher notes, standards, assessment, and references are provided. This book selection also includes the Table of Contents, Dedication, Preface, Introduction, and Index..