Decision Making Decision method

Delphi Method

Refines independent expert judgments through feedback rounds while retaining disagreement.

Delphi elicits judgments from a deliberately selected panel whose members remain anonymous to one another. Following an independent first round, everyone receives the same aggregated feedback and may revise their judgment with reasons. Prespecified rules determine sufficient stability or consensus.

Core question

What share of our customers will require digital evidence by the end of 2028?

Delphi Method planning Method guide

Start comparison

Give feedbackIs this method useful to you?

Participants: 6-30 Experten
Time: 2–3 rounds over several weeks; about 20–40 minutes per response.

A survey initiative spanning weeks. Planner minutes describe a working meeting; panel response windows are additional.

Anonymous individual judgments pass through feedback loops to form a distribution.

Protocol
Set panel and rules
Pilot an unambiguous question with a horizon and scale; specify expertise and panel perspectives.
Elicit
Collect independent judgments
Members respond without seeing other judgments; collect estimates and reasoning separately.
Feedback
Return distribution and reasons
Return median, range and balanced anonymous counterarguments, including minority views.
Conclude
Report stability and disagreement
Compare rounds against prespecified criteria, accounting for attrition and panel changes.

Run two or more rounds under an agreed protocol; start a new series when new evidence warrants revisiting the final report.

A good fit when

For uncertain forecasts or expert judgments where direct evidence is limited and several perspectives are needed.

Ideal for

Forecasting
Expert Judgment
Strategic Uncertainty

Not good for

Quick team decisions
Questions without relevant expertise

Outputs

Traceable panel judgment
A comparison of rounds including response counts, distributions, reasoning, attrition and uncertainty.

Delphi

Fictional example

Question and panel

What defined quantity is judged by which expert perspectives?

Customer share requiring digital evidence by end-2028; five people from sales, compliance, purchasing, product and industry research.

Prespecified rules

Which scale, feedback and stopping rules apply?

0–100%; median, range and arguments. Stop after round 2 if median changes by ≤5 percentage points; otherwise maximum 3 rounds. Stability is not consensus.

Round 1

What anonymous judgments and reasons were submitted?

P1 30%, P2 40%, P3 50%, P4 60%, P5 80%; median 50%, range 50 points. Different assumptions about procurement cycles.

Feedback and round 2

What was returned and how did judgments change?

Everyone receives the same distribution and counterarguments. New estimates: 40, 45, 50, 55, 70%; median 50%, range 30 points; no attrition.

Conclusion

Which stopping rule applies and what remains uncertain?

Median change 0 points meets the stability rule. Report a stable panel midpoint of 50%, not consensus; P5 expects faster regulatory adoption.

All situations and people are fictional.

RAND · Methodological Guidance for Delphi Panels

First step

Define the question, panel criteria, anonymity, analysis and stopping rule before inviting participants.

Open the method guide

Where to go next?

Paper illustration of a decision table with criteria rows, weighted ratings, and a narrowly leading alternative.

Decision Making

Decision Matrix

Weighs the options named in the panel report against fixed criteria.

Decision Making

Risk Matrix

Turns the reported uncertainty into an assessed risk list.

Deep dive

Purpose

When knowledge is distributed and direct dominance should be avoided, groups quickly fall under the sway of their opinion leaders. The Delphi Method gathers assessments iteratively and gradually brings expert judgments closer together.

How it works

Several independent rounds reconcile expectations, reasoning, and uncertainties with one another. Through feedback, extreme positions become testable without early loudness distorting the picture. The procedure pays off when solid approximations matter more than quick apparent precision.

In detail

The Delphi Method uses repeated anonymous assessment to condense expert judgments without individual voices dominating. Precise questions, controlled feedback, and documented assumptions keep the procedure solid. The result is not a mere average but a reasoned consensus with visibly remaining uncertainty.

Facilitation

Prepare a precise question, shared assumptions, and clean materials so the first round stays independent and focused. Its strength shows once ranges get traced back to differing premises rather than to authority. In the end, a reasoned condensation, open uncertainty, and clear pointers for further data collection are needed.

The method guide walks execution through 4 phases, timing, 4 pitfalls, and clear stop criteria.

Open method guide

Your perspective

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Sources and topics

Topics

Forecasting Experts Decision Strategy

Sources

RAND · Methodological Guidance for Delphi Panelsrand.orgRAND Corporation; a tools page on the Delphi method RAND developed in the 1950s for structured expert elicitation.

Artifact templates

Delphi Method: WorksheetRefine independent expert judgments through feedback rounds while retaining disagreement.

markdown

delphi-method-working-template.md

Refine independent expert judgments through feedback rounds while retaining disagreement.

Delphi Method: Worksheet

Question

To be confirmed

Desired outcome

To be confirmed

Scope

Plan the survey Time: 2–3 rounds over several weeks; about 20–40 minutes per response.

Complete this worksheet on paper or in your own document during the work.

Preparation for this scope

Method setup

Materials: Panel criteria, questionnaire, anonymous IDs and a procedure for medians, dispersion and arguments.
Roles: Study lead, independent expert panel and analysts; disclose interests and affiliations.
Advance information: Definitions of customer share and digital evidence, baseline information and the forecast horizon.
Overall time needed: 2–3 rounds over several weeks; about 20–40 minutes per response.
Setup: Pilot the questionnaire, announce feedback and deadlines, and keep identities separate from published answers.

Prepare for the work steps

Protocol: Set panel and rules

Question and selection criteria

Elicit: Collect independent judgments

Piloted questionnaire

Feedback: Return distribution and reasons

Anonymous distribution and reasoning

Conclude: Report stability and disagreement

All rounds and attrition log

Delphi

Question and panel

What defined quantity is judged by which expert perspectives?

...

Prespecified rules

Which scale, feedback and stopping rules apply?

...

Round 1

What anonymous judgments and reasons were submitted?

...

Feedback and round 2

What was returned and how did judgments change?

...

Conclusion

Which stopping rule applies and what remains uncertain?

...

Enter your own information; connect open commitments to a next action.

RAND · Methodological Guidance for Delphi Panels

Protocol: Set panel and rules

Expected artifact: Prespecified survey rules

A purposively selected panel is not a random sample.

Entry:

...

Are selection, scale and stopping rules set before answers arrive?

Elicit: Collect independent judgments

Expected artifact: First-round distribution

Independence precedes the first feedback.

Entry:

...

Were initial judgments independent of group feedback?

Feedback: Return distribution and reasons

Expected artifact: Reasoned subsequent round

Minority reasoning is relevant information.

Entry:

...

Does feedback include dispersion and counterarguments, not just the median?

Conclude: Report stability and disagreement

Expected artifact: Panel report with limits

Stability concerns changes across rounds; consensus concerns agreement.

Entry:

...

Are stopping rules, attrition and remaining disagreement traceable?

Open questions and next steps

...

Method guide: https://methodatlas.meierhoff-systems.de/en/methods/delphi-method/run-sheet

Alternatives and neighbors

Fitting alternatives with decision guidance, followed by other related methods.

All methods

Business Strategy

Scenario Planning

Instead of Delphi Method, when you want to work with multiple future scenarios instead of planning only one course of events.

Decision Making

Wideband Delphi

Moves options, criteria, and risks toward a concrete result through "clarify the estimate object and unit", "collect independent estimates", and "document another round and the outcome".