Balancing User and System Control in Shape-Changing Interfaces: a Designerly Exploration

Despite an increasing number of examples of shape-changing interfaces, the relation between users' actions and product movements has not gained a great deal of attention, nor been very well articulated. This paper presents a framework articulating the level of control offered to the user over the shape change. The framework considers whether the shape change is: 1) directly controlled by the user's explicit interactions; 2) negotiated with the user; 3) indirectly controlled by the users actions; 4) fully controlled by the system. The four types are described through design examples using ReFlex, a shape-changing interface in the form of a smartphone. The paper concludes that shape-changing interfaces tend to assign the control to either the user or the underlying system, while few (e.g. [16,28]) consider sharing the control between the user and the system.