Skillful is a five-level series of textbooks that is distinguished by its focus on developing individual language skills in the context of academic language requirements. All levels of the course include content, text types, and statements typical of the world of science. The course actively introduces and reinforces words from the Academic Word List that often appear in academic texts. Additionally, the Skillful series places special emphasis on non-linguistic areas useful to students, such as Study Skills, i.e. proven techniques, learning strategies, and information analysis, or Critical Thinking.