FOSS (Full Option Science System) is an inquiry based science program. Younger elementary students engage in science investigations in which they describe, sort, and organize observations about objects and organisms.  Upper elementary school students construct more advanced concepts by classifying, testing, experimenting, and determining cause and effect relationships among objects, organisims, and systems.  All students participate in activities that are multi-sensory, provide student-to-student interactions and require discourse and reflective thinking.