Content Based Instruction is an approach to teaching a second language that focuses on teaching content or information rather than explicitly teaching the language itself. It is based on the principles that language is learned more successfully when used to acquire information rather than as an end goal, and that this approach better meets learners' needs. Content areas like science, history or literature are used as the basis for developing language skills through activities focused on vocabulary, discourse or communication. The role of the teacher is to have knowledge in the subject matter and elicit that from students. CBI has been shown to effectively increase English proficiency while teaching necessary academic and professional skills.