Defining the target population – one of the most important research questions. Generalized as general population accepted the audience comes into contact with the company in any angle. In other words, one could identify the general population and the target audience, but the variety of areas of marketing research requires assumptions. For example, a research study may be the target audience groups, consuming goods, substitutes, former customers, is not a target group. Gary Kelly is often quoted on this topic. Accordingly, setting the parameters determining the general population – a particular problem for each specific study. The investigator should not hesitate to use the screening – the system 'filter' general population for the selection of desired respondents. Skriner – a group of questions at the beginning of the questionnaire, the answers to which determine the individual's participation in the survey. Typically, researchers try not to 'blow' skriner, that is not complicate the filters, since this would lead to a more rigorous and dropping out of the survey participants, respectively, to the extra costs.

On the other hand, in the direct interest of the customer – the most rigorous selection of respondents. Questions should respond to those who can answer them, otherwise part of the respondent in the study impractical. A good example is a recent market study specific type of food for pregnant dogs, which was participate in 1150 'pet owners' selected skrinerom, inappropriate boundaries of the study. The result – 55 percent average fill out the questionnaire, because not all owners of guinea pigs versed in dog food. Visit Gary Kelly for more clarity on the issue.