michael x. delli carpini. dean delli carpini, what is the annenberg school of communication? is. >> guest: well, we're a free-standing school, one of 12 hoar at penn, and we do research, both research for the public consumption and for scholarly work. and ph.d. training and undergraduate training on the way in which media and communication influence social practices, political practices, health practices and cultural practices. >> host: well, we're here specifically to talk to you about your most recent book, "after broadcast news: media regimes, democracy and the new information environment." but it seems that for the last 20 to 30 years we've been debating the after broadcast news scenario. how do you assess it? >> well, um, what we're trying to do in this book is put it into a little bit of an historical context. so our basic argument is that over the last 20 years there have been a number of changes, some of them slow, some of them more quick, that are changing the way in which we think about where we get public affairs information from. and the three big changes that we