We all think we know what television is. After all, we talk about it all the time. But my concept of what television currently is has been changing. Three recent events confirmed to me that television is evolving in a direction that requires a change in definition. The first indicator was Nielsen, which recently announced that for the second year in a row, its estimated TV Universe for the United States will decline. It is a small decline, they say, but in an industry that has seen Universe growth every year for the past 60+ years, two consecutive years of decline indicates a seismic shift. (The Television Universe is the number (or percentage) of all homes in the U.S. with at least one TV set capable of receiving at least one TV signal. It is a hardware-based definition.) The second indicator was last week, when I was asked to lecture at CCNY as part of a corporate communications class. I spoke about media, changing technologies, return-path data and media research to the students. Then I asked them what the word “television” meant to them. Some said it was the set itself. Some said it was programming. But after further discussion, many decided that television was video content wherever they viewed it, whether on a tablet, a mobile device, a computer or on an actual television set. In fact, almost all the students in a class of 50 said that they view content on several devices at some point in an average week. Viewing in front of the set was a different viewing experience -- one that was often shared with family members -- but a considerable amount of their viewing time was multiplatform. The third indicator that television is shifting was at Multichannel News’ TV in a Multi-Platform World Conference on May 3. It was there that some of the best technological minds in the media business talked about the concept of television in an increasingly multiplatform environment. Whether it was the advancement of HBOGo (an app for HBO subscribers that gives them access to all episodes to all series on demand) as a way to increase subscriber satisfaction, or whether it was a discussion of the impact of social media on driving overall viewership, the endpoint was the same. Television is no longer discussed as hardware. It has become a generic term relating to content, wherever that content resides. But has the measurement of television kept pace with the technology? Should the definition of the Nielsen TV Universe be expanded to include second and third (or more) screens so it can more effectively capture all forms of “television” viewing? Some have already formed a way to compare social media to Nielsen measurement. Marc Debevoise of CBS Interactive said that a 9% increase in social buzz is said to equal a 1% increase in a Nielsen rating. It’s a start, anyway. But maybe its time to reassess the role of television in the media marketplace. I think we have moved beyond defining television as a piece of stationary hardware that sits in a room in a home or a dorm. The reality is that television has expanded, whether we are talking about second-plus screens or video content. If that’s true, then the television universe is not eroding; it’s instead expanding rapidly and perhaps uncontrollably. Revising our terms and definitions is the first step. The next step is how to best measure television across all possible platforms. But that's another column….