Ambiguous computing (or ludic computing) is sub-branch of human-computer interaction (HCI) concerned with how ambiguity can be used as a resource for creating more engaging computer systems. By leveraging the fact "ambiguous situations require people to participate in making meaning" designers can thus relinquish control to the users in interpreting the system. The important pioneers in this field are William Gaver and Phoebe Sengers. Ambiguity in design originated in cultural probes as a method for user research. However, it was later adopted in actual design prototypes and artifacts.