What is the Delphi Method and How Do You Use It in Surveys?

Need an expert opinion? The problem with expert opinions is, if you aren’t satisfied with it, you’ll want a second opinion. And then maybe a third or forth. The Delphi research method provides a solution to that by essentially combining experts’ opinions and whittling them down into one final answer. Of course, it is more complex than that. This blog will dive into the Delphi methodology and how it works.

What is the Delphi Method?

The Delphi methodology gathers a number of expert opinions and insights on a particular topic or issue. It aims to reach a consensus of opinion among this group, usually by conducting a series of surveys. At the end of the series of Delphi surveys, the hope is that some general consensus will be reached. The Delphi method is particularly useful when dealing with complex or uncertain issues where there might not be a single “correct” answer, but by tapping into the collective wisdom of experts, there may be a “convergence of opinion.”

History of the Delphi Method

The Delphi method was developed in the 1950s as a way to gather expert opinions in order to address complex or uncertain problems. The name ‘Delphi’ comes from the ancient Oracle of Delphi, a woman who resided in a Greek temple near Athens, and who was known to provide advice. Here are some key events in its development.

1950s: The RAND Corporation, a nonprofit think tank in the United States, created the Delphi research method as a systematic way to collect and combine expert opinions for military and policy-related issues.

1960s: The Delphi method gains more recognition as important researchers of the time use it for technology forecasting.

1970s-1990s: The Delphi method expands across more disciplines, such as education planning, economic forecasting, and health care decision making.

2000s-Present: The method continues to evolve, with online and digital tools being integrated into the process. This makes it easier to engage experts from around the world. 

Today, the Delphi method is widely recognized as a great way to handle complex and uncertain problems by bringing in a diverse group of experts to assist in decision making.

5 Steps of the Delphi Method in Research

There are five main steps in the Delphi research method. They are as follows:

1. Participant Selection

A group of experts within a particular subject area are selected for the study. They may be located anywhere in the world and often don’t know one another.

2. Round-Based Surveys Begin

Next, multiple rounds of surveys or questionnaires are conducted with each expert to gather their opinions, predictions, and rationales. The questions may be qualitative and quantitative in nature, and question types can be open-ended or structured.

3. Feedback and Iteration Collected

After each round of surveys, the responses are analyzed, summarized, and made anonymous. The aggregated results are then shared with the participants in the subsequent round. Participants are encouraged to revise their opinions or answers based on the collective insights from the group. 

4. Round-Based Surveys Continue

Round-based surveys or questionnaires are again distributed to the experts, often several rounds, until a general consensus or convergence of opinions is reached, or until a predetermined stopping point is reached.

5. Analyzing the Convergence of Opinions

With the surveying rounds complete, researchers narrow down the range of opinions and identify areas of agreement or disagreement among the experts. The goal is to reach a more refined and informed perspective on the research topic.

Pros and Cons of the Delphi Method

Like all types of surveys, there are pros and cons to the Delphi method. Here’s a look at each.

Advantages of Delphi Method

  • Expert Consensus. By combining the collective expertise of a diverse group of experts, the Delphi method helps reduce individual biases and provides a more comprehensive view of the topic.
  • Anonymity. Participants can remain anonymous which reduces the potential for conflict or dominance by a few outspoken members of the group.
  • Flexibility. The Delphi method works in various fields and disciplines, making it adaptable to a wide range of research contexts.
  • Structured Process. Through round-based surveys, the Delphi process allows for refining and clarifying opinions over time, leading to increased accuracy and reliability.
  • Objective Interpretation. Decisions based on experts are likely to be efficient.

Disadvantages of Delphi Method

  • Resource-Intensive. The Delphi method can be time-consuming and almost always involves several rounds of surveys and data analysis.
  • Expert Availability. Securing a panel of qualified experts who are willing to participate can sometimes be a challenge.
  • Expensive. It is often expensive to retain experts for the numerous rounds of surveys they will need to engage with.
  • Subjective Interpretation. The process of reaching a consensus might involve the subjective judgment of the researcher in determining when to stop the survey rounds and consider an agreement as reached.

Delphi Method vs. Other Research Methods

So how does the Delphi method stack up against other types of survey methods? People often compare it to focus groups and interviews. While these methods do provide qualitative insights, the Delphi method allows for the aggregation and quantification of expert opinions, making it more suitable for reaching consensus. In addition, focus groups generally gather all participants in one room or on one call. This can lead to dominant personalities overtaking the conversation and others holding back, potentially skewing results.

Traditional surveys, whether conducted via mail or online, generally offer just a single round of data collection. The Delphi method, which uses round-based surveying, allows for refining and revising opinions over multiple surveys. This helps to arrive at a consensus.

Uses of the Delphi Methodology

The Delphi methodology aids researchers in many different ways!

1. Decision-Making 

The Delphi method can forecast future trends or outcomes. Experts provide their opinions on different scenarios, and through iterative rounds of feedback and discussion, a consensus is within reach. This helps organizations and others make more informed decisions.

2. Technology

Using the Delphi method, experts can provide insight into the potential impact of emerging technologies and innovations. This allows organizations to better plan and adapt for the future.

3. Risk Assessment

The Delphi method can help identify and assess the potential risks of a project, policy, or decision. Experts contribute their insights on various risks and their potential consequences, helping organizations develop risk management strategies.

4. Policy Development

Delphi helps with formulating and evaluating policy. Experts from relevant fields provide input on proposed policies, regulations, or initiatives. This helps ensure smart policies put together from a wide range of perspectives.

5. Market Research

The Delphi method in market research efforts gathers expert opinions on consumer preferences, market trends, and emerging needs. By consulting marketing gurus, organizations can better understand their customers needs and wants, and adjust their strategy. Delphi can also help with developing new products that consumers are looking for.

6. Healthcare

Delphi is applicable in healthcare where expert opinion can help save lives. Surveys may ask medical professionals about medical diagnoses, treatment, and public health initiatives. 

7. Product Innovation

When developing new products or technology, the Delphi method helps gather insights from experts about potential features, design considerations, and market viability. This helps ensure that products align with customer needs and industry trends.

8. Education

Delphi can aid in design or update educational curricula at any grade level. Experts offer their thoughts on subject matter, learning objectives, and teaching methods, with the goal of giving students well-rounded and effective education programs.

9. Public Opinion Analysis

After surveying the public through traditional surveys or online surveys, researchers analyze the results, looking at social attitudes, behaviors, and more. Next, they suggest ways organizations and officials can communicate with the public better.

10. Environmental Planning

Delphi is great for environmental planning and sustainability initiatives. Experts contribute their insights on environmental issues, potential solutions, and strategies for sustainable development.

Real-life Delphi Method Example

Here’s a look at the Delphi method in action. The Delphi method example uses a in which a health care company wants to gather insights from a diverse group of medical experts to identify the most likely trends in medicine over the next 10 years.

To apply the Delphi method, the company first identifies medical experts in a variety of fields. These experts come directly from the health care field or from academia.

Round 1: The company designs a survey with open ended questions, such as “Where do you think we’ll make the most significant medical progress in the next decade?” Experts submit their anonymous responses online.

Feedback and Iteration: The company compiles the responses, extracts key themes, and presents an anonymized summary of the experts’ opinions in a report. In the next round, experts are provided with the summary and are asked to reconsider and potentially revise their initial responses in light of the collective insights.

Round 2: The revised survey includes more questions based on the themes and ideas from the first round. Experts provide their opinions, and the agency again compiles and summarizes the results.

Convergence of Consensus: The agency continues this iterative process for several rounds (about 2 to 4 rounds) until the experts’ opinions start converging towards a consensus on the future trends in medicine. Each round refines the opinions and allows the experts to react to the aggregated insights from the group.

Final Report: Once a consensus or a “convergence of opinions” is achieved, the company puts together the final report, outlining the identified trends, potential challenges, and key drivers that are likely to influence medicine in the next 10 years. The report shows areas of consensus as well as areas where expert opinions were different.


When seeking expert opinions, and wanting the opinions to be generally agreeable, the Delphi method is the best tool for the job. Another great tool for the job? SurveyLegend. Your experts can engage with our online surveys as many times as needed to reach a convergence of opinion. The surveys can be as fun or as professional as you wish, anonymous or not, and they’re highly secure offering great protection for the often confidential information involved in a Delphi study.

Have you conducted a survey using the Delphi method in the past? Let us know how it went in the comments!

Frequently Asked Questions (FAQs)


What is the Delphi method definition?

The Delphi method gathers expert opinions on a particular topic. It aims to reach a consensus of opinions among a group of experts through a series of surveys.

Who uses the Delphi methodology?

Companies often use the Delphi method when looking for an expert opinion (based upon many experts’ opinions). From marketing research to healthcare research, the Delphi method is valuable across many different disciplines.

What is a Delphi survey?

A Delphi survey is one that is sent out to people multiple times until they reach a consensus (sometimes they will not). This survey usually uses open ended questions to get everyone thinking out of the box.

About the Author
A born entrepreneur, passionate leader, motivator, great love for UI & UX design, and strong believer in "less is more”. A big advocate of bootstrapping. BS in Logistics Service Management. I don't create company environments, I create family and team environments.