The Delphi method is a process of systematically structuring human communications while relying on "a group of experts who anonymously reply to questionnaires and subsequently receive feedback in the form of a statistical representation of the" round of group responses. Through a process of iteration, the goal is to achieve group consensus from the reduction of the range of responses of expert opinions, ideas, and words.
The Delphi method originated from defense research. An United States Air Force-sponsored Rand Corporation study from the 1950's called "Project Delphi" was commissioned to investigate the use of expert opinion. The study looked to apply "expert opinion to the selection, from the point of view of a Soviet strategic planner, of an optimal U. S. industrial target system and to the estimation of the number of A-bombs required to reduce the munitions output by a prescribed amount." The alternative method to studying the aforementioned problem during the 1950's would be to conduct extensive and expensive data collection, programming and implementing computer models so large that the computer size would have been a major prohibitive factor for the kind of computers available back then.
The Delphi method is useful "for use on complex or ambiguous problems that exceed the capabilities of a single person." Furthermore, the method could be applied when "accurate information is unavailable or expensive to obtain, or evaluation models require subjective inputs to the point where they become the dominating parameters."
- In research using group interaction, a person's attitudes and opinions do not develop in a closed system and that individuals need to take account of others' opinions, ideas, and knowledge so that he or she can develop their own. 
- Group judgments are more valid than individual judgments.
- More participants can be involved than a face to face method allows.
- The anonymity of participants is kept.
- Provides a structured way for a group of people to make decisions in a political or emotional environment about complex problems.
- Research participants avoid direct confrontation with other experts.
- Researchers are able to "signiﬁcantly extend the empirical observations upon which
their initial theory is based—thus strengthening the grounding of the theory and increasing the likelihood that the resulting theory will hold across multiple contexts and settings."
- The Delphi process can be quite time-consuming.
- Anonymity may lead to lack of accountability.
- The process can be easily influenced by the coordinator.
- Expert bias is a strong possibility.
- A middle opinion is more likely to emerge due to the tendency to remove extreme expert opinions.
Examples in Informatics:
- Goossen WT, Epping PJ, Dassen T. Criteria for nursing information systems as a component of the electronic patient record: an international Delphi study. Comput Nurs. 1997 Nov-Dec; 15(6): 307-15.
- Hübner-Bloder G, Ammenwerth E. Key performance indicators to benchmark hospital information systems - a Delphi study. Methods Inf Med. 2009; 48(6): 508-18. Epub 2009 Nov 5.
- Iljaž RJ, Meglič M, Svab I. Building consensus about eHealth in Slovene primary health care: Delphi study. BMC Med Inform Decis Mak. 2011 Apr 18; 11: 25. doi: 10.1186/1472-6947-11-25.
- Staggers N, Gassert CA, Curran C. A Delphi study to determine informatics competencies for nurses at four levels of practice. Nurs Res. 2002 Nov-Dec; 51(6): 383-90.
- Delphi Method [Internet]. [Place unknown]: RAND Corporation; 1994 [updated 2011 Jan 29; cited 2012 Nov 25]. Available from http://www.rand.org/topics/delphi-method.html.
- Dalkey N, Helmer, O. An experimental application of the Delphi method to the use of experts. Management Science. 1963 Apr; 9(3): 458-467. doi: 10.1287/mnsc.9.3.458.
- Ciałkowska M, Adamowski T, Piotrowski P, Kiejna A. What is the Delphi method? Strengths and shortcomings. Psychiatr Pol. 2008 Jan-Feb; 42(1): 5-15.
- Linstone HA, Turoff M. The Delphi method: Techniques and applications. Reading, Mass.: Addison-Wesley; 1975.
- Reed J, Payton VR. Focus groups: Issues of analysis and interpretation. J Adv Nurs. 1997 Oct; 26(4): 765-771.
- Okoli C, Pawlowski SD. The Delphi method as a research tool: an example, design considerations and applications. Information & Management. 2004 Dec; 42(1): 15-29. doi: 10.1016/j.im.2003.11.002.
Submitted by AiLien Truong