The Human Function Model, as described in the University of Kentucky Assistive Technology Project, places assistive technology in its proper perspective, as an external support that can enhance an individual's ability to function within the environment. The National Assistive Technology Research Institute groups assistive technology and related services in seven categories that define an individual's needs: (1) existence (2) communication (3) body support, protection, and positioning (4) travel and mobility (5) environmental interaction (6) education and transition and (7) sports, fitness, and recreation. Using these devices can help students with disabilities actively participate in the classroom.