手法を比較

	Weak Signal Analysis	STEEP Structured Scanning
分野	Futures Foresight Studies	Futures Foresight Studies
系統	Process / pipeline	Process / pipeline
提唱年	1975	2003
提唱者	H. Igor Ansoff	Foresight scanning tradition (categorized macro-environmental scanning); Joseph Voros (generic foresight process)
種類	Early-warning pipeline for graduated response to faint strategic signals	Categorized horizon-scanning pipeline for signals of change
原典	Ansoff, H. I. (1975). Managing strategic surprise by response to weak signals. California Management Review, 18(2), 21-33.	Voros, J. (2003). A generic foresight process framework. Foresight, 5(3), 10-21.
別名	Weak Signals, Ansoff Weak-Signal Analysis, Strategic Issue Early Warning, Graduated Response to Weak Signals	STEEP Analysis, STEEP Horizon Scanning, STEEP Framework Scanning, Categorized Environmental Scanning
関連	4	4
概要	Weak signal analysis is H. Igor Ansoff's approach to managing strategic surprise by responding to faint, ambiguous early indicators of discontinuity long before they harden into unmistakable trends. Ansoff's 1975 argument was that organizations relying on strong, well-confirmed signals are condemned to react too late, because by the time a discontinuity is obvious the room to maneuver has collapsed; the alternative is to detect change while it is still a whisper and to graduate the response as the signal strengthens. The method rests on a ladder of knowledge states — from a vague sense that something is stirring to precise quantitative understanding — matched to a ladder of responses, from heightened awareness through increased strategic flexibility to direct action. As codified in the Millennium Project's Futures Research Methodology, weak signal analysis turns scanning from passive observation into an early-warning system that trades the certainty of late information for the maneuvering room of early, tentative response.	STEEP structured scanning is a categorized horizon-scanning method that systematically sweeps the external environment for signals of change and sorts them into five domains — Social, Technological, Economic, Environmental, and Political. By imposing a fixed five-part taxonomy on an otherwise unbounded flood of information, STEEP forces analysts to look beyond the dimensions they habitually monitor and to give balanced attention to forces that might otherwise be ignored. The framework operationalizes the input or scanning stage of Joseph Voros's generic foresight process, providing the raw material of signals, trends, and emerging issues that later analysis interprets. As documented in the Millennium Project's Futures Research Methodology, categorized scanning is one of the foundational practices of strategic foresight, valued precisely because its discipline counteracts the natural tendency to over-monitor the familiar and under-monitor the surprising.