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: