Personal-interview SURVEYS are one method market researchers use to collect information. Personal interview surveys are often conducted to collect information about customer needs and wants, opinions, demographics, and financial status. Personal-interview research can be conducted in peoples’ homes, businesses, prearranged focusgroup locations, or public places. One of the most popular forms of personal-interview research is the mall-intercept method, where researchers set up in the walkway or in a booth at shopping center and ask shoppers to take part in the survey. Personal-interview surveys allow for in-depth questioning of respondents and the use of visual materials. They also allow for flexibility in collecting data and can be conducted quickly, yielding fairly high response rates. Respondents can be shown videotapes, pictures, and prototypes of new PRODUCTs. In addition to their responses to survey questions, respondents’ nonverbal responses—e.g., expressions of surprise, concern, or excitement—can also be assessed. Personal-interview questions are usually structured to gather additional information from respondents. In addition to asking typical questions about what products people use or do not use, like or dislike, interviewers can ask about motivations—e.g., why people do or think the way they do. The disadvantages of personal-interview surveys are the expense and the potential for interviewer bias. Except for the focus-group method, only one respondent can be interviewed at a time, and interviewers often spend considerable time traveling to meet respondents. Since personal-interview methods are expensive, companies often use them when they cannot obtain the information using other methods and when the information is critical to business decisions. An additional cost is interviewer training. To obtain consistently objective data, interviewers must be trained to avoid interjecting bias through the tone of language used or nonverbal cues. Personal-interview methods, particularly mall-intercept surveys, are used to test product and promotional concepts. In the famous 1980s Coke/new Coke disaster, researchers used a mall-intercept method to ask people to taste samples of the cola and state which they preferred. A slight majority preferred the new Coke formula, and based on this research, Coca-Cola Company replaced the traditional formula. When consumers protested, the company realized they had not asked consumers how they felt about traditional Coca-Cola. Using the personal-interview method, this information could have been gathered and the problem avoided.
See also FOCUS GROUPS; QUESTIONNAIRES.