Take a field trip to a location where water and land meet to study patterns of sediment organization in wet habitats: river or ocean beaches, sand dunes, tidal marshes, the edge of a pond, or a woodland stream. Small groups collect pairs of sediment samples in plastic jars. (Have families send in clean peanut butter jars.) Back in class, they explore variables that affect sediment movement and particle size. Finally, everyone combines their samples in a class jar to see what happens when particles of different sizes coexist. This plan features excellent preparation guidance, followup, and a bibliography.