A Dual Immersion program is an instructional model that provides content-based instruction to students in two languages where the goal is for the students, over a number of years of participation in the program, to become proficient and literate in both languages, while also meeting high academic standards in all subject areas. Other terminology that is commonly used for one of the variations of this type of program model is Dual Language, Two-way Dual Language, One-way Dual Language, Partial Immersion, Full Immersion, etc. Typically, programs begin at kindergarten or 1st grade and continue through elementary school, and, if possible, into middle and high school.
Definition from: https://www.k12.wa.us/WorldLanguages/DualImmersion.aspx (accessed 10/1/2012)