A delphi study (or simply just ‘delphi’) is a type of research involving a series of surveys to gather people's opinions about a topic, and then use these opinions to refine and develop recommendations.
Participants are asked to give their opinions on a series of statements by voting on whether each statement is important or not, and whether it should be changed. Statements which are popular (receive the highest votes) are carried forwards to the next survey. Those which are unpopular (receive the lowest votes) are removed. Comments can be provided to allow the researchers to make some of the statements better.
For example - a statement might read “Healthcare should be equally high quality for every person, regardless of their wealth, sex, or ethnicity”. Participants are likely to vote this statement is important, but may comment that we should add “gender identity, race, and age” to the statement.
When every participant has had the chance to vote, the researchers will go through the results and make any changes suggested in the comments. Statements which were voted as unimportant will be removed altogether. The same list of participants will then be asked to vote again on the new amended statements. The amended statements which the participants now rate as unimportant are removed. This process continues until all remaining statements are voted of ‘high importance’ from most of the participants.
At this stage, a final meeting is usually held between participants. At the meeting, each of the successful statements is discussed in more detail, and a panel votes for a final time on whether they should be included. This final meeting achieves ‘consensus’ - an agreement between people on a final list of recommendations.