Determining What’s Better: Single or Multiple Attitudinal Measures

Summary

Academic researchers tend to use multiple items to measure a construct reliably, whereas practitioners tend to use single-item measures. But when constructs such as brand attitude, attitude toward the advertisement, and attitude toward behaviors are double concrete — i.e., with a clear, singular meaning in which the object being rated also is clear and singularly identifiable—a single-item measure suffices (Rossiter, 2011). Using the results of 189 advertising studies, the authors found no difference in effect sizes when the double-concrete dependent variables were measured with single or multiple items. This result: data collection is more efficient and less tedious. Specific learning includes:

• Studies that use single-item measures do not differ in effect size from those that use multiple-item measures.

• The number of items used to measure attitudes does not influence the effect of the independent variables on attitudes.

• If a construct has a clear and singular meaning and the object being rated also is clear and identifiable, then a single valid item is all that is needed.

• The study’s results strongly suggest that the double-concrete precept is generalizable.