Introduction
There are a number of techniques for making predictions or analysis. It is particularly useful in governments, public policy, and other areas where facts may be disputed but generally based on a set of common foundational knowledge. Examples of this type include economics (where the same economic principles may be expressed differently by country), and psychology (where, for instance, suicide risk assessments may coe to different results but be based on the same risk factors.)
The Delphi technique is a simple but very powerful technique to leverage the power of experts to make decisions, particularly in areas where prediction or forecasting are important. It was named for the Delphi Oracle that figured in Greek mythology, a priestess famous for her prophecies.
How the Delphi Technique Works
The Delphi technique involves selecting a panel of experts to answer the question at hand. This is usually one with some debate; for instance, suicide risk assessment methods have been tested by presenting cases to experts who make their decisions in a method similar to the Delphi Technique.
Once you have a decision that needs to be made, a panel of experts, and a question to be answered, each expert receives the question and information requires independently. After answering, their judgements are displayed to all of the panelists.
In some variations, the experts are shown who among them made each contribution, but in others this information is kept anonymously. Then, the experts complete a second round; having seen the decisions (and usually, the rationalizations) that led to each of the expert’s decisions, they are free to revise their original forecast.
This process repeats until there is either complete agreement in the process (a rarity, indeed), or the experts are no longer willing to revise their predictions. This technique can also be used with non-experts, but is primarily designed to harness their specialized knowledge.
Examples of the Delphi Technique
One practical example of how the Delphi technique was applied was in validating the Suicide Intervention Response Inventory, a tool to evaluate the responses of helpline volunteers. The questions involved were given to a series of experts and their responses were used to formulate the “expert” answers. A person’s score then, is the degree of variance from their responses and the expert panel’s average response.