Decision Making Exercise: The Delphi Method

Decision Making Exercise: The Delphi Method


This exercise can be used to demonstrate the Delphi method of decision making and forecasting to the delegates. It is an excellent technique to use in meetings where everyone has to voice their opinion and the group wants to make a decision based on the opinion of all the experts present. The method has a systematic feedback and encourages independent votes irrespective of other voter’s seniority or authority. The Delphi method was originally developed in the cold war to estimate the dangers of nuclear war. 


Delegates must estimate the number of objects in a container using a variation of the Delphi method.

What You Need

  • A container full of a number of items. Examples are:
    • A jar full of gherkins
    • A jar full of little plastic animals
    • A jar full of small river stones (you can make it even more difficult by including variable sized stones in the jar)
  • A pack of small post-it notes or other papers in the same size (4 or 5 times the number of participants)


  • Place the paper at the centre of the table where everyone can access as you go through the rounds.
  • Show the jar from where you stand. Ask the delegates to estimate the number of items inside the jar.
  • The delegates should write their estimates on paper, without sharing with each other and then pass it to the tutor.
  • The tutor should calculate the average of the estimations and then state this figure to all delegates.
  • Now ask the delegates to estimate again and write on new papers similar to round 1.
  • Collect estimates, average and tell them the new figure.
  • Continue with 2 or 3 more rounds.
  • Now reveal the true figure and compare with their final average estimate.


Explaining the Test: 5 minutes.

Activity: 15 minutes

Group Feedback: 10 minutes.


Ask the delegates how they felt while they were making the estimates? How did they respond to the estimated average of the contents? Was the average getting closer in every round to the true figure? Was group decision better than the individual decisions? Why?

Explain that the feedback leads to shared decision making which improves the quality of the estimations. Emphasise that the group can make better decisions especially if team members have access to shared information. In addition, the estimation becomes more accurate as political biases are removed from people’s decision making process which is why the Delphi method is carried out anonymously and the sources of comments or not revealed even after the decision is made.

You may choose to explain the Delhi method in more detail at this point so that the delegates learn how to use this technique in their everyday life.

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