The "School in a Box" contents are a combination of materials to facilitate learning of 3-5 year olds in their first formal learning environment. The materials are selected to improve teacher performance and facilitate learning and development in several domains: social, cognitive, physical, emotional, language and communication. The package of materials included in the "Box" has been evolving based upon feedback from teachers, availability of materials, and cost. Efforts are made to unify the package of materials to a national standard which is supported by all providers, regardless of source of funds.