Asking Questions - The Definitive Guide To Questionnaire Design ...

ASKING NONTHREATENING QUESTIONS ABOUT BEHAVIOR 75
Thus, as we shall see in the next chapter, long questions are useful
for behavior that may be socially undesirable but may lead to an
overreporting of socially desirable behavior.
Using Respondents as Informants
Up to this point we have mostly assumed that respondents are
reporting only their personal behavior. For cost and availability reasons,
you will often want respondents to report about other members
of the household, and you may sometimes even want them to
report about friends or organizations. Thus, one household informant,
usually the principal shopper, may be asked to report about
food purchases of all household members; a mother may be asked
about the illnesses and doctor visits of all her children. Or one adult
may be asked to report on the voting behavior of all other adults in
the household.
You would expect, and research confirms, that reports about
others are generally 10 to 20 percent less accurate than reports
about the respondent’s own behavior, unless that behavior is threatening
(Marquis and Cannell, 1971; Menon, Bickart, Sudman, and
Blair, 1995). Informants learn about the behavior of others by participating
in the activity with them, observing them, or talking
with them about it. In some cases, the informant may not know
about the behavior. For example, children may purchase snacks
away from home or participate in leisure activities that parents
don’t know about. The behavior may also be unimportant and
hence go unnoticed, such as purchasing personal care products or
listening to the radio. In still other cases, the behavior, such as a
minor illness, may not be salient and may even be forgotten by the
person who was not directly involved.
However, if the respondent does know about the salient behavior,
such as a hospitalization or voting, information from informants
may be highly reliable. The use of informants is especially efficient
when you are screening the population for specific qualities, such as
for people who golf or who are Gulf War veterans. False positives