Face-to-face Delphi Technique
Also known as: in-person Delphi, face-to-face Delphi, conventional Delphi, FtF Delphi
The face-to-face Delphi Technique is a structured, iterative consensus-building method conducted through in-person sessions with a purposively selected panel of experts. Across multiple rounds, panelists independently respond to structured questionnaires, receive aggregated group feedback, and revise their judgments until acceptable consensus is reached. The face-to-face format adds direct interpersonal interaction while preserving the anonymity of individual ratings within each round.
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When to use it
Use the face-to-face Delphi when you need structured expert consensus on complex, contested, or future-oriented questions and when all panelists can feasibly attend in-person sessions — for example, a regional expert committee or an institutional working group. It suits policy prioritisation, curriculum design, clinical guideline development, and technology forecasting. Prefer it over remote Delphi when immediate clarification of ambiguous items is important or when faster iteration matters. Do NOT use it when experts are geographically dispersed and travel is impractical; when you need large samples (>50 panelists); when the research question is empirically answerable with primary data rather than expert judgment; or when group dynamics in a shared room risk undermining anonymity of responses despite the protocol's safeguards.
Strengths & limitations
- Structured anonymity of ratings reduces conformity pressure and status bias better than unstructured group discussion.
- In-person contact allows the facilitator to clarify questionnaire ambiguities immediately, improving response quality.
- Iterative feedback enables genuine opinion change grounded in evidence rather than social pressure.
- Produces documented, quantified consensus that is transparent and auditable.
- Well-suited to complex forecasting and priority-setting tasks where no single expert holds complete knowledge.
- Face-to-face format typically accelerates the consensus timeline compared to asynchronous remote rounds.
- Logistically demanding: all experts must travel to a common venue for each round, limiting panel size and geographic diversity.
- Consensus is social and structured, not statistical — results cannot be generalised to a population in a probabilistic sense.
- Panel composition is purposive; selection bias in expert recruitment can systematically skew outcomes.
- Even with anonymity protocols, physical co-presence may subtly suppress dissent from junior or lower-status panelists.
- Defining and operationalising consensus is methodologically contested — threshold choices affect which items pass.
Frequently asked
How is face-to-face Delphi different from a focus group?
Both methods bring experts together in person, but they differ fundamentally in structure. A focus group is an open, facilitated discussion where participants hear and respond to each other in real time. Face-to-face Delphi deliberately suppresses real-time mutual influence: ratings are made individually and anonymously within each round, and group feedback is only shared as aggregated statistics between rounds. Delphi elicits refined individual judgment; focus groups surface social interaction and collective sense-making.
How many rounds are needed?
Most face-to-face Delphi studies use two to four rounds. The stopping rule should be defined prospectively: either a stability criterion (ratings do not shift meaningfully between consecutive rounds) or a consensus threshold on IQR. Three rounds are common in health and education research. Adding rounds beyond four yields diminishing returns and increases dropout risk.
How large should the expert panel be?
The literature most commonly recommends 10–30 panelists for face-to-face Delphi. The lower bound ensures sufficient diversity of perspective; the upper bound reflects practical limits of room-based facilitation and the logistics of assembling co-located experts. Panels below 10 risk idiosyncratic results; panels above 30 are better suited to remote Delphi formats.
Does face-to-face mean individual anonymity is lost?
Not necessarily. Physical co-presence means panelists know who is in the room, but well-designed protocols collect ratings privately (on paper ballots or individual devices) before revealing any aggregated results. Panelists do not see each other's individual scores — only the group distribution. This preserves the epistemic benefits of anonymity even when identities are known, though facilitators should monitor for subtle social pressure during debriefs of outlier positions.
When should I choose remote Delphi instead?
Choose remote Delphi when experts are geographically dispersed, when travel costs are prohibitive, when the panel needs to exceed 30 participants, or when asynchronous reflection time between rounds is methodologically valuable. Face-to-face is preferable when rapid iteration, immediate item clarification, and facilitated discussion of outlier rationales are priorities and when all panelists can realistically attend.
Sources
- Dalkey, N., & Helmer, O. (1963). An experimental application of the Delphi method to the use of experts. Management Science, 9(3), 458–467. DOI: 10.1287/mnsc.9.3.458 ↗
- Linstone, H. A., & Turoff, M. (Eds.). (1975). The Delphi Method: Techniques and Applications. Addison-Wesley. link ↗
How to cite this page
ScholarGate. (2026, June 3). Face-to-face Delphi Technique. ScholarGate. https://scholargate.app/en/survey-methodology/face-to-face-delphi-technique
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
- Delphi TechniqueSurvey Methodology↔ compare
- Face-to-face Focus GroupSurvey Methodology↔ compare
- Focus GroupQualitative↔ compare
- Nominal Group TechniqueQualitative↔ compare
- Online Delphi TechniqueSurvey Methodology↔ compare