interchangeably, even though there is a distinction.

The mental effort for a rank-order question is almost exponential – N*(N-1)/2 – since each item has to be compared to every other item.

Because the effort grows rapidly as more items are added, it is commonly advised to only use ranking questions when there are seven or fewer items to compare.

Think about whether the items being asked about are expected to be very similar or very different from one another.

For instance, when asking people to rate the importance of items about why they did business with your organization or why they purchased a product, many attributes are of similar importance, making a rating scale appropriate.

Alternatively, when asking people what features you should work on next, where you need to build a priority list for your development team, a ranking question may be more appropriate.

The literature is muddied on which approach is most reliable.

Early Krosnick research ("Maximizing Questionnaire Quality", 1999) saw ranking questions as having greater predictive validity, but a number of studies since, include his own later research, show rating questions as having greater validity (Krosnick, Thomas, and Shaeffer, 2003; Maio, Roese, Seligman, Katz, 1996).

Sometimes you will want to consider alternatives such as Max Diff or constant-sum questions.

Atlanta home builder KM Homes knew its website was outdated, and after searching for a company to bring their website into the 21st century, they chose Marketing RELEVANCE to help.