Interactivity is defined as an activity made to respond to the user and causes the user to respond back in a certain way (Barfied, 2004, pp.9). Barfield (2004, pp.9-10) suggests that interaction design is about paying attention to the design of the interactive aspects that the user perceives and communicates with. With other similar terms like interactive and interaction, debates on the exact definition of interactivity are still ongoing as its demands are still often misunderstood by designers.

It's revolutionary.
As Shedroff (2006) stated in his website, interaction could be defined as a response experience in which communication or conversation between two parties, the actor and reactor, are engaged in a mutually affecting experience. Experiencing interactivity is a reciprocating experience of participation between two parties which can now be created to involve a viewer's entire body and all senses; providing one with the ability to influence and to be influenced by their world (Ritter, D., 2005). So interaction should be explored as an intervention that expands the relationships among the audience, allowing them to create, change and intervene with events in a meaningful way (Marini, 2006).

Interaction design allows us to understand how various experiences can be cultivated to "support the goals and messages of any communication" by creating rich, affecting and engaging experiences (Shedroff, 1994, pp.2, Shedroff, 2006). But it is no longer just about interaction design; it is about creating and manipulating experiences. Only with experiences can knowledge thrive and communication be considered effective. The development of interactivity consists of overlapping disciplines such as interaction, information, sensorial design and experience design. Shedroff (1994, pp.2) felt that different disciplines are significant because "they define the boundaries with which we can create and communicate".