Leonard , Ryan E 1 ; Heckman , Christoffer 2 ; Minear , J. Toby 3 ; Anderson , Robert S 4 1 University of ÃÛÌÇÖ±²¥ at Boulder, Department of Computer Science 2 University of ÃÛÌÇÖ±²¥ at Boulder, Department of Computer Science 3 University of ÃÛÌÇÖ±²¥, Boulder and Cooperative Institute...