More Than Books. The classroom is also filled with all kinds of learning tools: mobile devices, art supplies, low- and high-tech materials for do-it-yourself projects, equipment for tinkering, and other materials as determined by the unique needs of the learners. The use of flexible, interactive learning environments is supported by research on the ways in which spatial environments affect student learning. The HEAD Project (Holistic Evidence and Design), in a study of the impacts of the classroom environment on the learning rates of students, noted six factors that are particularly influential to learning progress: light, user choice, flexibility, connections (as in corridors and the ways different areas fit together), complexity (such as having different types of learning areas), and color. The 21st-century classroom mimics the look, feel, and energy of people’s favorite informal learning spaces: coffee shops, libraries, maker spaces, art galleries, parks, and museums. They are places where students want to go and spend hour after hour of their time engaged in deep and meaningful learning.