McCormick+Schmitz Handbook for value chain research on - PACA

selection of a few illustrative case studies than it would be if the method were used to
construct a larger sample from which the <strong>research</strong>er might be tempted to generalise the
findings.
Quota sampling is another <strong>for</strong>m of non-probability sampling frequently used in settings
where it is difficult to obtain a sampling frame. The quota is the exact number or
minimum number of units to be selected. In quota sampling, interviewers are told to look
<strong>for</strong> certain characteristics, but they are not told precisely whom to interview. So, <strong>for</strong>
example, a <strong>value</strong> <strong>chain</strong> study might include consumer interviews to determine attitudes
towards clothing from certain countries. Interviewers might be sent to shopping malls to
do 100 interviews divided according to
gender: 50 men and 50 women;
age: 40 from the ‘under 30' group, 40 between the ages of 30 and 60, and 20 over 60;
education: 50 with high school education or less and 50 with more than a high school
education.
The result is a series of accidental samples, but since the parameters are controlled, the
result is more likely to be representative of the population than is possible with an
accidental sample.
A.5.2 Questionnaire writing
Be<strong>for</strong>e beginning to write the questionnaire, you need to think about its eventual
administration. A questionnaire that will be distributed and filled by the respondent is
necessarily different from one that will be administered in a face-to-face interview.
Interview questionnaires tend to be favoured in developing countries <strong>for</strong> a number of
reasons. Low education levels mean that many people would have difficulty completing a
questionnaire alone. Many societies are multilingual, and it can be difficult to determine
the respondent’s preferred language in advance. In many countries unreliable postal
systems make it unwise to count on questionnaires sent through the mail either arriving or
being returned. Finally, in many societies there is a clear preference <strong>for</strong> face-to-face over
written communication. Nevertheless, a questionnaire that is completed by the respondent
is sometimes appropriate, even in developing countries. If you need detailed personnel
data or financial in<strong>for</strong>mation from a company, it is usually better to arrange to have an
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