Communication modes refer to the categories of behavior used to communicate. These modes include eye gaze, vocal modes (vocalizations and speech production), gestural modes body movements, pointing, sign and conventional gestures), and graphic modes (photographs, line drawings and symbols). Many students will use a combination of modes to communicate. For example, for some students, speech is their first means of communication and other systems such as a picture board may be used to help make the oral communication more understandable, or the other system may serve as a means of circumventing word retrieval or oral language formulation problems. Another example may be a student with a limited verbal vocabulary might use an augmentative communication system and use signs to express communicative intentions (Read more about augmentative communication system).