手法を比較

	適応型自然実験	フィールド実験
分野	実験計画法	実験計画法
系統	Process / pipeline	Process / pipeline
提唱年	2000s–2010s (systematic application in policy and social science evaluation)	1920s–1930s (agriculture); 1990s–2000s (social sciences)
提唱者	Synthesizes natural experiment tradition (Meyer 1995; Dunning 2012) with adaptive design principles (Wald 1947; Chow & Chang 2008)	Formalized by R. A. Fisher (1935); systematized in social sciences by Harrison & List (2004)
種類	Quasi-experimental adaptive research design	Experimental design
原典	Dunning, T. (2012). Natural Experiments in the Social Sciences: A Design-Based Approach. Cambridge University Press. ISBN: 978-1107698000	Harrison, G. W., & List, J. A. (2004). Field experiments. Journal of Economic Literature, 42(4), 1009–1055.
別名	adaptive quasi-experiment, adaptive exogenous shock design, adaptive as-if randomization, sequential natural experiment	field trial, natural field experiment, randomized field experiment, field RCT
関連	4	5
概要	An adaptive natural experiment combines the causal logic of the natural experiment — exploiting real-world events that assign individuals to conditions in a plausibly exogenous way — with pre-specified adaptive monitoring rules that allow the analytic protocol to be modified based on accumulating data. This hybrid design is used in economics, epidemiology, and policy evaluation when the natural event unfolds over time and interim evidence can legitimately inform decisions about data collection scope, subgroup focus, or analytic strategy without compromising causal validity.	A field experiment applies the logic of a randomized controlled trial in a naturally occurring, real-world environment rather than an artificial laboratory. Participants are randomly assigned to treatment and control conditions while going about everyday activities, allowing researchers to estimate causal effects with high internal validity while preserving a level of ecological realism that laboratory settings cannot offer. The design is especially prominent in economics, public health, political science, and development research.