A critical underpinning of the whole area of audience measurement is the definition that is used for viewing. Although it is critical, it is also very difficult to get to grips with, because of the nature of the measurement process. Existing peoplemeter systems require both the adoption of a practical definition so that respondents can be given guidance on what is required of them, and also the rather more abstract definition that must inevitably be used when the always incomplete data is received from the meters. Although the people meter has been much criticized for its operational aspects, and the possibilities for incomplete or erroneous data, the proposed passive systems will also suffer similar problems of definition, without the compensation of input from the respondents. This paper makes the point that through the people meter, respondents do get the opportunity to give us some guidance of their intentions, and wonders whether in adopting a passive system any potential gains in the supposed better pick-up of viewing will not actually represent a decrease in the real reflection of viewer behavior.