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

ASKING NONTHREATENING QUESTIONS ABOUT BEHAVIOR 65
doing when Pearl Harbor was attacked, when President Kennedy
was assassinated, or when the World Trade Center collapsed on
September 11, 2001. In contrast, habitual events, such as all the
things that one did at home and work, would be difficult to remember
for even a day or two.
In general, the greater the cost or benefit of an activity, the
more one is likely to remember it. Winners of $100,000 in a state
lottery will remember the details better than will the winners of
$25. The purchase of a $500 microwave oven is easier to remember
than the purchase of a $.69 potato peeler. Juvenile shoplifters will
remember the time they were caught and forget the details of successful
shoplifting efforts. Finally, some events result in continuing
reminders that the event happened. The presence of a house, car,
or major appliance is a reminder that the purchase was made. The
presence of children is a reminder of their births.
Many behavioral events are salient along two or three dimensions.
Thus, buying a house is a unique event; it requires payment of
a very large sum of money, and the presence of the building acts as a
continuing reminder. On the other hand, the purchase of a food
item is a low-cost, habitual act with no continuing consequences.
Within this framework, memory about highly salient events is
satisfactory for periods of a year or possibly more. Unfortunately, little
work has been done on periods much longer than a year. However,
for highly salient events, such as major accidents or illnesses,
periods of two or three years appear to be possible. Periods of two
weeks to a month seem to be appropriate for low-salience events.
For behaviors of intermediate saliency, periods of one to three
months are most widely used. Choosing an optimum time period
does not mean that the data will be error free, but only that errors
will be minimized if recall procedures are used.
Longer Time Periods for Summary Information. When summary
information is available, longer time periods can be used. Many
respondents can give fairly reliable estimates of total medical expenditures,
expenses for vacations, or income received in the past