In the early 20th century, two Columbia University researchers, Samuel Torrey Orton and Anna Gillingham, developed the Orton-Gillingham approach to reading. The Orton-Gillingham approach favors a multi-sensory, immersive study of language, and it has been in widespread use since the 1930s. Instructors use the Orton-Gillingham method to teach students of all ages, and it is useful for both young children and adult literacy programs. The approach encourages students to understand not just reading, but how humans acquire language and learn more generally. The approach is highly structured and sequential in nature.