As additional insight about Delphi method, there is the notion that construction engineering and management (CEM) researchers often rely on alternative research techniques when traditional methods fail. In contemporary research, the Delphi method is particularly useful when objective data are unattainable; when there is a lack of empirical evidence; experimental research is unrealistic or unethical, or when the heterogeneity of the participants must be preserved to assure validity of the results (Hallowell & Gambatese, 2009). Despite its application to CEM research and other research approaches, this well-defined and highly successful research technique has not seen widespread use. Several factors may contribute to the limited use of the Delphi method (Hallowell & Gambatese, 2009).
Hallowell, M. R., & Gambatese, J. A. (2009). Qualitative research: Application of the Delphi method to CEM research. Journal of construction engineering and management, 136(1), 99-107.
