手法を比較

	対面型デルファイ法	構造化合意形成手法としてのナショナル・グループ・テクニック（NGT）
分野	調査方法論	質的手法
系統	Process / pipeline	Process / pipeline
提唱年	1950s–1963	1971
提唱者	Norman Dalkey and Olaf Helmer (RAND Corporation)	André L. Delbecq and Andrew H. Van de Ven
種類	Structured expert-consensus method	Qualitative research method
原典	Dalkey, N., & Helmer, O. (1963). An experimental application of the Delphi method to the use of experts. Management Science, 9(3), 458–467.	Delbecq, A. L., & Van de Ven, A. H. (1971). A group process model for problem identification and program planning. Journal of Applied Behavioral Science, 7(4), 466–492.
別名	in-person Delphi, face-to-face Delphi, conventional Delphi, FtF Delphi	NGT, structured group process, nominal group process, priority-setting group method
関連	5	6
概要	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.	The Nominal Group Technique (NGT) is a structured group facilitation method designed to generate and prioritise ideas, problems, or solutions while ensuring equal participation from all members. Developed by Delbecq and Van de Ven in 1971, it combines silent individual idea generation with structured group discussion and systematic voting to produce a ranked list of priorities. Unlike unstructured focus groups, NGT prevents dominant voices from suppressing quieter participants, making it especially valuable for needs assessment, program planning, and stakeholder priority-setting in applied research and policy contexts.