Reducing undecided voters and other sources of error in election surveys

The present study found the number of undecided voters on forced-choice que stions about candidate preferences was roughly three times higher than that on subjective probability questions, and that election predictions based o n traditional forced-choice scales had a higher degree of error than predic tions based on subjective probability scales. The findings show that subjec tive probability scales can introduce error when there are more than two ca ndidates or parries in an election, but this can be easily corrected by the procedure for adjusting subjective probability scores that was used by Hoe k & Gendall (1993). While the use of adjusted probability scores improved t he accuracy of predictions in multi-candidate races, no difference was foun d in the accuracy of predictions based on adjusted and unadjusted probabili ties in elections with only two candidates.