Content Based

Content – based
Introduction
There has been a number of theoretical foundations for content-based, which includes second language acquisition research and work in educational and cognitive psychology. After all content – based has been positioned as a necessary instruction for successful second language acquisition. Content-based instructions differs from traditional second language teachingmethods in different ways . Teachers have to select the content material they will use in their classes, the language teacher have to exploit the material for its language teaching potential because the content material dictates a selection and sequence of teaching points, which means that the teacher must become familiar enough with the content material tu put it to a meaningful use. This is oneof the most difficult, indispensable but necessarily requirements for content- based teaching.

Historical overview
According to Krashen (1984) second language acquisition occurs when the learner receives comprehensible input. He states that “comprehensible subject-matter teaching is language teaching”. In content based instruction the focus is on the subject matter and not on the form asKrashen says “what is being said rather than how”.
Acording to different studies based on Canadian inmersion programs, Swain (1985,1994)states that to receive comprehensible input, they must produce comprehensible output, which means explicit attention must be paid to the productive languages skills of speaking and writing. She maintains that that learners need “to be pushed toward thedelivery of a message that is…conveyed, coherently, and appropriately”. In addition Content-based instruction can provide this push since students learn to produce language which is appropriate in terms of both content and language.
More research fundations in content- based have been used to support the cognitive academic language learning approach. Anderson (1993) had work in research learningtheory and his theory reinforces teaching approaches which combine the development of language and content knowledge, practice in using this knowledge, and strategy training promotes independing learning. He also states that Content-based approaches promote extended practice with coherent content coupled with relevant language learning activities such as teaching how knowledge structures can berealized , through language and content (see Mohan 1986, Tang 1992, 1997)
In other hand Grabe and Stroller (1997) note that effective content-based instructional approaches “combine coherent and interesting informational resources to create increasing, but manageable, task complexity”
What is content- based?


MODELS OF CONTENT BASED
There are different content-based models and they aredifferent from each other. They are distinguished by setting or context (some models are use in foreing language setting and others in second language context), instructional level (as a content teaching elementary school level or secondary and postsecondary levels) , and we can also distinguished the degree of emphasis on language and content.
There are 5 models of content based instruction. Thefirst two are models design to teach foreing languages to English Speaking children at elementary school level, and the other three models have been implemented in secondary and postsecondary language settings.
I. IMMERSION EDUCATION
It was first established in 1965 in a suburb of Montreal, Canada. This Model is one of the most carefully researched language programs. Immersion childrenconsistently perform at or above grade level scholastically and they are part of monolingual peers in English language development, so by this immersion at the end of elementary school they students become bilingual.
Early immersion becomes in Kindergarten or 1st grade. A middle immersion or delayed immersion starts in middle elementary grades usually Fourth grade. And finally late immersion...