Nielsen began informing clients this week that it has officially decided to change the way it defines television to include non-traditional sources of TV viewing such as Internet-connected devices in its TV ratings sample households, and will make those changes effective with the start of the 2013-14 television season in September. The two most significant implications of those changes are that Nielsen will begin including Internet-only TV households in its sample, and will also start measuring viewing on Internet-connected TVs in its existing sample households. While Nielsen will also modify its official TV universe estimates as a result of the changes, executives said the impact will only be about six-tenths of a percentage point. The material impact on actual TV ratings and usage levels is expected to be small when the changes are made, but Nielsen executive said they need to make the changes now because the role of Internet-connected TV is likely to grow and become more of a factor in the future. “There is definitely a potential to have an impact, but we think it is only going to be about six-tenths of a [percentage point],” explains Brian Fuhrer, senior vice president-national & cross-platform product leader at Nielsen. “We don’t think it’s going to be dramatic.” Whatever the actual impact is on total TV viewing estimates, Fuhrer said it will not impact the official trading currency used by advertisers and agencies -- such as the so-called C3 ratings in national TV negotiations -- because Nielsen will be storing the data from the Internet-connected households and TVs in a “separate bucket.” The reason is that C3 ratings represent the television audience for the average of all commercial minutes, and that much of the viewing done via the Internet-connected TVs is to alternatives sources such as online video or Internet-based platforms like Hulu and Netflix that make TV programming available without their original commercial loads. One exception, he said, is alternative television delivery systems such as Comcast's Xfinity service, which provide conventional television programming and advertising via the Web. One of the most interesting aspects of the change is the fact that Nielsen will be including so-called “zero TV profile” households in its samples -- homes that don’t receive any traditional TV signals via terrestrial, satellite or cable TV. While they represent a small percentage of total viewing, and typically are either younger (college or post-college) or economically challenged households, their demographics and behaviors will be new to television audience measurement, and could represent valuable insights for the future as more homes become Internet-only connected. To date, Nielsen has been keeping records on such households it had contacted but bypassed in previous recruiting efforts, and will begin recontacting them to become part of the sample. Fuhrer said Nielsen will spend the next several weeks contacting customers and trade groups to explain the impact and implications of the changes, and he noted that some of them have wanted Nielsen to move faster on the changes, while others want Nielsen to move more slowly. He said Nielsen has been weighing both sides, but made the decision to redefine television now, because the changes manifesting in the way consumers actually watch television are moving so fast. He said another redefinition of television that would include viewing on wireless connected devices including smartphones, tablets and even TVs connected to wireless gadgets in the near future, but that no date has been set for that.