It's all in a name. When is a 'Delphi study' not a Delphi study?

As nursing researchers we need to fully understand the origins of the methods we are using in research investigations. Without an in-depth understanding, we may find ourselves violating fundamental underpinning assumptions or conventions through ignorance, and the resulting studies are unlikely to stand up to tests of congruence and rigour. This paper is a discussion of some complexities encountered while exploring the literature on the Delphi technique, a research method we had believed to be straightforward. The Delphi method had been used extensively since its development in the 1950s, and its use in nursing research appears to be increasing. Our explorations revealed that, rather than a simple means of obtaining the judgments of experts, modifications and adaptations over the years have dramatically changed 'the' Delphi. Anyone wishing to use the method needs a sound knowledge of complex theoretical issues associated with its implementation.