The Index of Learning Styles (ILS) is an instrument used to assess preferences on four dimensions (active/reflective, sensing/intuitive, visual/verbal, and sequential/global) of a learning style model developed by Richard M. Felder and Linda K. Silverman. A student's learning style profile provides an indication of probable strengths and possible tendencies or habits that might lead to difficulty in academic settings.
Research suggests that "The optimal teaching style strikes a balance (not necessarily an equal one) between the poles of each dimension of the chosen learning styles model."