At the recent Device Design Day (D3) event organised by Kicker Studios Wendy Ju shared her work on implicit interactions. You can see the lightweight slides for her presentation, or read her paper below.
“Implicit interactions enable communication without using explicit input or output. One way that an interaction can be implicit is if the exchange occurs outside the attentional foreground of the user. This occurs in traditional computing-when the computer auto-saves your files, or filters your spam e-mail, for instance-as well as in ubiquitous computing interaction. The other way that an interaction can be made implicit is if the exchange is initiated by the computer system rather than by the user-if the computer alerts you to new mail, or when it displays a screensaver. (It may seem counter- intuitive that something that grabs your attention could be implicit, but it is important to remember that the interaction is based on an implied demand for information or action, not an explicit one.)”
Link: The Design of Implicit Interactions: Making Interactive Systems Less Obnoxious (stanford.edu)