Content-based instruction (CBI) is a significant approach in language education (Brinton, Snow, & Wesche, 1989). CBI is designed to provide second-language learners instruction in content and language.
Historically, the word content has changed its meaning in second language teaching. Content used to refer to the methods of grammar–translation, audio-lingual methodology and vocabulary or sound patterns in dialog form. Recently, content is interpreted as the use of subject matter as a vehicle for second or foreign language teaching/learning.
The CBI approach is comparable to English for Specific Purposes (ESP), which usually is for vocational or occupational needs or English for Academic Purposes (EAP). The goal of CBI is to prepare students to acquire the languages while using the context of any subject matter so that students learn the language by using it within the specific context. Rather than learning a language out of context, it is learned within the context of a specific academic subject.
As educators realized that in order to successfully complete an academic task, second language (L2) learners have to master both English as a language form (grammar, vocabulary etc.) and how English is used in core content classes, they started to implement various approaches such as Sheltered instruction and learning to learn in CBI classes. Sheltered instruction is more of a teacher-driven approach that puts the responsibility on the teachers' shoulders. This is the case by stressing several pedagogical needs to help learners achieve their goals, such as teachers having knowledge of the subject matter, knowledge of instructional strategies to comprehensible and accessible content, knowledge of L2 learning processes and the ability to assess cognitive, linguistic and social strategies that students use to assure content comprehension while promoting English academic development. Learning to learn is more of a student-centered approach that stresses the importance of having the learners share this responsibility with their teachers. Learning to learn emphasizes the significant role that learning strategies play in the process of learning.