Lengthy questionnaires are not appropriate. Personal surveys provide in-depth answers, meeting respondents face to face. In a focus group interview , a researcher meets with a group so 8 to 12 people to discuss a particular product or topic. Interviews may be videotaped or audiotaped. Focus groups are best used as exploratory research.
Researchers can talk with respondents individually at their home or office or at a mall.
Individual interviews conducted in shopping centers are known as mall intercepts. Talking with people in their homes or offices is costly, but can provide unique data. An experiment is a scientific way of comparing and measuring data under controlled conditions. The second element, the dependent variable. Experiments can be conducted in a laboratory setting or in the field.