手法を比較

	オンライン・デルファイ法（e-Delphi）	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	Original Delphi: 1950s–1960s; Online variant: mid-1990s onwards	1971
提唱者	Olaf Helmer, Norman Dalkey, Nicholas Rescher (RAND Corporation); online adaptation emerged in the 1990s–2000s	André L. Delbecq and Andrew H. Van de Ven
種類	Iterative expert consensus method (online)	Qualitative research method
原典	Hasson, F., Keeney, S., & McKenna, H. (2000). Research guidelines for the Delphi survey technique. Journal of Advanced Nursing, 32(4), 1008–1015.	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	e-Delphi, electronic Delphi, web-based Delphi, internet Delphi	NGT, structured group process, nominal group process, priority-setting group method
関連	5	6
概要	The Online Delphi Technique (e-Delphi) is an iterative, web-mediated consensus method in which a geographically dispersed panel of experts responds to successive rounds of structured questionnaires distributed and collected via email or a web platform. Anonymous feedback and controlled statistical summaries are fed back between rounds, guiding panellists toward convergence on priorities, predictions, or recommendations without the social pressures of face-to-face group discussion.	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.