20 CHAPTER 3 REVIEW OF CONJOINT ANALYSIS THEORY ...

interviews is the difficulty for interviewers to hold the attention of respondents for more
than 15 minutes.
The advantages of mail surveys include their relatively low cost, ease of
administration, and geographical flexibility. Pictures and diagrams can also be included
in the questionnaire. The disadvantages of using mail surveys are their characteristically
low response rates, and the need for follow-up surveys to increase response rates. Also,
respondents may interpret some questions incorrectly and as a result, provide incorrect
answers. For this study, a mail survey was used because the conjoint section of the study
required respondents to rank different biotech labeling characteristics.
Questionnaire
A questionnaire was developed which was divided into six sections. They
included a section on consumer awareness and perceptions of biotech foods, (2) questions
on mandatory or voluntary labeling, (3) a conjoint experimental design on labeling
formats, (4) questions on the purchasing of biotech foods, (5) questions regarding the
consumer’s use of food labels, and (6) questions on consumer demographics. A copy of
the questionnaire appears in appendix A.
The first part of the questionnaire provided background information on
biotechnology. It included a definition, the present and future uses (benefits), and
examples of present applications of the technology. This was followed by 12 questions
regarding the respondent’s general knowledge of, and their attitudes toward
biotechnology. Following this introductory section, respondents were asked to choose
between a mandatory labeling or a voluntary labeling policy for biotech foods. A second
question asked respondents to choose the minimum percentage of genetically modified
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