It is not just active participation, but, it is active participation where choices are made that affect the outcome. I think that interactivity is where the viewer helps shape the final product along with the broadcaster. I also feel that interactivity has a close link with the usage of computers, in particular, the internet. In a sense, radio has been an interactive broadcaster for a long time. For years radio has been encouraging listeners to call in with their opinions, news tips and to win contests.
Radio is interactive because there is a two way connection and flow of information.
Currently, television shows claim to be interactive if you can phone, fax, e-mail, and dial up their web site for more information. Most television shows make the interactive claim with that reasoning behind it. More information possible in easier ways does not make television interactive. Interactivity brings television to a new and different level. It makes television an active activity as opposed to a passive activity where the viewer just has to sit without even thinking.