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S
URVEY
G
UIDE
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explicit, rather than leaving each respondent to make an assumption about how
far back they should try to remember.
It’s best to use specific dates rather than referring to “last week” or “last month,”
and the length of the reference period needs to be appropriate to the behavior or
event the respondent is being asked to recall. It might be difficult for many
people to recall how many times they’ve
eaten in a restaurant during the past six
months, but most of us could be pretty accurate about how many times we ate in
a restaurant during a recent two-week period described with specific dates.
The place to announce the reference period is in the preamble at the beginning
of a section of related questions and whenever the reference period changes. It
is also helpful to repeat the reference period in abbreviated form as you ask
each question in the series.
R
ESPONSE
F
ORMAT
Questions must match the desired format of the answer. For example, if you are
providing separate blanks for the city and the state of residence, ask In which
city and state do you live? rather than Where do you live?
If you provide response categories for a question, make sure they are
exhaustive
–
i.e., all respondents can identify one that fits (less than 20 years,
20-60 years, over 60 years). Categories should also be mutually exclusive so
that respondents can easily select only one response (0-9 and 10-19 rather than
0-10 and 10-20). Ensuring that response categories are both exhaustive and
mutually exclusive may require re-evaluating the intent of the question or
separating it into two or more questions, or both.
Response categories labeled with words (dissatisfied, satisfied) give more
reliable data than categories labeled with numbers (1, 5). The researcher can
always assign numeric values later to make it easier to analyze responses.
Categories should be fully labeled with exactly what each point on the scale
means (very dissatisfied, somewhat dissatisfied, neither satisfied nor
dissatisfied, somewhat satisfied, very satisfied).
For questions that only ask about one dimension (e.g., how satisfied are you?),
five fully labeled categories are usually sufficient. For bipolar questions (e.g.,
how satisfied or dissatisfied are you?), use seven fully labeled categories. The
midpoint should allow for mixed or in between feelings, whichever is most
appropriate.
When measuring the frequency of an event or behavior, ask for the actual
number of times the event or behavior occurred during the reference period,
rather than providing categories like often, seldom, never.