On the limits of research rigidity: the number of items in a scale

Deciding whether to use single-versus multi-item scales remains a controversial topic (Bergkvist 2015; Bergkvist and Roberts 2007; Kamakura 2015). Much of the fervor behind the single-versus multi-item scale discussion stems from an understandable desire to (a) find the "right" answer and (b) to automate and standardize research methods. Unfortunately, there rarely, if ever, is an approach that strictly dominates all others. All approaches have pros and cons-i.e., highlight some things well and leave others in the shadows. Here, we discuss some of the pros and cons of using single-versus multi-item scales, arguing against employing rigid rules and for a goal-directed and flexible measurement approach.