The purpose of this assessment probe is to elicit students’ ideas about an everyday object in the sky—clouds. It is designed to determine whether students recognize that clouds are made up of tiny droplets of water or tiny ice crystals. Elementary students’ emphasis should be on observing and describing clouds as well as other forms of visible water in the air, such as fog and mist. Middle school students expand their experiences to more conceptual ideas about the composition and formation of clouds. High school students should know what clouds are made of and how they are formed. Teacher notes, standards, assessment, and references are provided. This book selection also includes the Table of Contents, Dedication, Preface, Introduction, and Index.