Because the item, ''How concerned are you about ... ?'' asks responden
ts to indicate their level of concern about an issue, some respondents
may sense it assumes they are concerned or should be concerned about
the issue. Using a filter question to first determine if people are co
ncerned about the issue before asking for their degree of concern may
help solve this problem. To test this hypothesis, a split-ballot exper
iment was embedded in a national random digit dialing telephone survey
on food-related issues. For the four items included in the experiment
, the group receiving the filter versions of the questions gave roughl
y double the percentages of ''not concerned'' responses as the group r
eceiving standard items, and the filter group also gave fewer response
s at the upper end of the response scale.