Soshi Iba Christiaan J. J. Paredis Pradeep K. Khosla Interactive Multimodal Robot Programming. 83-104 2005 24 I. J. Robotic Res. 1 http://ijr.sagepub.com/cgi/content/abstract/24/1/83 db/journals/ijrr/ijrr24.html#IbaPK05