, ▁or ▁PS / 2 ▁port . ▁ ▁What ▁can ▁be ▁accomplished ▁with ▁a ▁switch ▁Switch es ▁can ▁be ▁suitable ▁for ▁people ▁with ▁cogn itive ▁difficulties , ▁development al ▁del ays ▁and ▁physical ▁limitations . ▁In ▁the ▁simplest ▁use ▁they ▁are ▁a ▁clear ▁and ▁simple ▁way ▁to ▁demonstrate ▁action / re action ▁often ▁referred ▁to ▁as ▁cause ▁and ▁effect . ▁In ▁the ▁more ▁complex ▁use ▁they ▁could ▁be ▁the ▁means ▁to ▁control ▁mob ility ▁or ▁interact ▁with ▁the ▁environment . ▁There ▁are ▁a ▁variety ▁of ▁motiv ating ▁switch ▁activities ▁that ▁can ▁be ▁used ▁to ▁assess ▁and ▁develop ▁a ▁person ' s ▁understanding ▁of ▁choice ▁and ▁timing . ▁ ▁Switch es ▁can ▁be ▁linked ▁to ▁a ▁variety ▁of ▁devices , ▁for ▁example : ▁Aug ment ative ▁and ▁Altern ative ▁Communic ation ▁devices , ▁switch ▁adapted ▁to ys , ▁switch ▁interfaces ▁for ▁computer ▁access , ▁S MA RT ▁Technology , ▁sens ory ▁room ▁equipment ▁and ▁environmental ▁control ▁devices ▁ ▁Switch ▁types ▁The ▁smallest ▁amount ▁of ▁interaction ▁that ▁can ▁be ▁provided ▁with ▁a ▁switch ▁is ▁binary ▁switch ▁input , ▁as ▁holding ▁down ▁the ▁switch ▁for ▁a ▁certain ▁amount ▁of ▁time ▁may ▁be ▁impossible ▁for ▁a ▁s ip ▁and ▁pu ff ▁device ▁or ▁pain ful ▁for ▁someone ▁with ▁ar th rit is . ▁ ▁Some ▁users ▁will ▁prefer ▁to ▁use ▁one ▁switch , ▁others ▁will ▁prefer ▁to ▁use ▁two ▁and ▁sometimes ▁more . ▁For ▁users ▁who ▁are ▁using ▁their ▁switch es ▁to ▁access ▁simple ▁activities ▁an ▁additional ▁switch ▁brings ▁about ▁an ▁option ▁of ▁choice . ▁It ▁also