The introduction section of the K-12 ASL Content Standards describes the general language development process, drawing from available research in ASL language acquisition and linguistics, upon which the ASL standards are based. The CCSS ELA are based on the research in language development that has taken place over many years. There are similarities in language development among languages. The Standards also address the most important aspect of ASL as a language; ASL is a visual language with some characteristics that are different from spoken languages. A reference list is included within the Standards document and on the Standards webpage.