The Delphi Method is a renowned technique initially developed by Olaf Helmer and Norman Dalkey in the 1950s. Our unique spin on this classic method challenges participants’ decision-making processes and highlights the impact of team synergy.
+ Main topic: Team synergy
+ Related topics:Cooperation and teamwork; decision-making; groupthink; authority gradients; psychological safety
+ Training length: 30 – 50 minutes (including debrief)
+ Included: Trainer instruction booklet, briefing and debriefing instructions
+ Number of participants: 3 – 20 participants
+ Access: Instant download after payment
Please note you can also access the exercise when buying our “Team Synergy” lesson plan.
*Images that depict exercise process are AI-generated
Instant digital download
Print-and-run – no equipment to order
Proves a group knows more than any one person
DELPHI© articipants privately estimate how many items – typically Lego bricks – are in a jar, without discussing their guess with anyone. After each round, the group’s average is shared, and everyone re-estimates; this repeats for two to four rounds. One or two participants are quietly told the correct number in advance, which becomes the focus of the debrief: despite being surrounded by information from other participants, most people barely adjust their initial guess.
The exercise gives you a concrete example of groupthink and authority gradients, and how structured, anonymous input can outperform open discussion.
Format
Trainer instructions delivered as an instant-access PDF download. No physical materials are shipped – you’ll need to supply your own transparent jar and 130–160 small items (e.g. Lego bricks, M&Ms, pasta spirals) plus note paper for participants.
Group size
3–20 participants. We recommend at least 5 for a stronger effect; there’s no formal maximum, though larger groups make collecting and averaging estimates more time-consuming.
Materials
Exercise instructions, trainer information sheet, briefing and debriefing instructions (digital download).
Fill a transparent jar with 130–160 small items (Lego bricks, M&Ms, etc.) and quietly tell one or two participants the correct count in advance, without letting the rest of the group know.
Each participant estimates, in complete privacy, how many items are in the jar.
Participants write down their estimate and hand it to you. You calculate and share the group’s average, then everyone re-estimates – repeating for two to four rounds.
Compare how far estimates converge toward the correct number, and use the planted “insiders” to explore why most people ignore group feedback in favour of their own judgement.
Fill a transparent jar with 130–160 small items (Lego bricks, M&Ms, etc.) and quietly tell one or two participants the correct count in advance, without letting the rest of the group know.
Each participant estimates, in complete privacy, how many items are in the jar.
Participants write down their estimate and hand it to you. You calculate and share the group’s average, then everyone re-estimates – repeating for two to four rounds.
Compare how far estimates converge toward the correct number, and use the planted “insiders” to explore why most people ignore group feedback in favour of their own judgement.
We have gathered the most frequently asked questions from our customers to help you in the best way possible
The exercise raises awareness of groupthink and the conditions that produce it, alongside the contrasting conditions that support team synergy and effective collective decision-making. It also introduces the impact of authority gradients and psychological safety on group judgement.
DELPHI works well as a short, thought-provoking exercise to introduce topics like decision-making, cooperation, and the “wisdom of crowds.” It’s also included with our Team Synergy lesson plan, if you’d rather buy it as part of a ready-made session. If you’re building or refreshing your own CRM training, our CRM Trainer Core Course covers how to structure and debrief exercises like this one.
Yes. The trainer booklet includes an extensive set of debrief questions covering groupthink, authority gradients, and psychological safety, plus example trainer-participant dialogue to help guide the discussion.
The exercise works with as few as 3 participants, though we recommend at least 5 for a stronger effect. There’s no formal maximum, but larger groups make collecting and averaging estimates more time-consuming – a practical cap of around 20 works well.
