手法を比較

	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）	Delphi Method
分野	質的手法	質的手法
系統	Process / pipeline	Process / pipeline
提唱年	1971	1963
提唱者	André L. Delbecq and Andrew H. Van de Ven	Norman Dalkey & Olaf Helmer (RAND Corporation)
種類	Qualitative research method	Structured iterative expert-elicitation process
原典	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.	Dalkey, N. & Helmer, O. (1963). An Experimental Application of the Delphi Method to the Use of Experts. Management Science, 9(3), 458-467.
別名	NGT, structured group process, nominal group process, priority-setting group method	Delphi Yöntemi, Delphi technique, expert consensus method
関連	6	5
概要	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.	The Delphi method is a structured, iterative survey technique developed by Norman Dalkey and Olaf Helmer at the RAND Corporation in 1963 for eliciting and converging expert opinion on complex topics where empirical data are unavailable or insufficient. It collects independent judgements from a geographically dispersed expert panel over multiple anonymous rounds, feeding aggregated results back to participants after each round so they can revise their views in light of the group's collective position.