“ BICS refers to the basic communicative fluency achieved by all normal native speakers of a language. It is cognitively undemanding and contentextual and is better understood as the language used by students in informal settings, say, on a playground or cafe. Research by Cummins as well as Virginia Collier suggest that it typically takes language learners 1-3 years to develop BICS if they have sufficient exposure to the second language.”
CALP refers to the ability to manipulate language using abstractions in a sophisticated manner.
CALP is used while performing in an academic setting.
CALP is the ability to think in and use a language as a tool for learning. Cummins' and Collier's research suggest that K-12 students need 5 to 7 years to acquire CALP in the second language if the learner has native language literacy. Learners who do not have strong native language literacy often need 7-10 years to acquire CALP in the second language.
Instructors of Bilingual educational environments, Cummins tells us, should be mindful that a student's apparent ability to interact at a high cognitive level on the 'street' does not necessarily imply the same cognitive or communications ability in the 'class'.
It is tempting for teachers and administrators to move students with a high BICS level into a 'mainstream' class because they 'sound' like the other kids on the playground.
Cummins insists that a more thorough assessment of the student's academic language abilities be performed before moving the student out of a 'sheltered' language development environment.
Cummins' common underlying proficiency model of bilingualism can be pictorially represented in the form of two icebergs.
The two icebergs are separate above the surface. That is, two languages are visibly different in outward conversation. Underneath the surface, the two icebergs are fused such that the two languages do not function separately.
Both languages operate through the same central processing system.