手法を比較

	クロスオーバー自然実験	クロスオーバー・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	Crossover designs: mid-20th century; applied to natural experiments: 1990s–2000s	1960s–1970s (field experiment framework); crossover application in non-clinical fields from 1980s onward
提唱者	Drawn from crossover trial methods (Jones & Kenward) and natural experiment tradition (Mill, 1843; Dunning, 2012)	Crossover design principles attributed to R. A. Fisher (1930s); field experiment tradition developed by Donald T. Campbell and Julian Stanley (1960s)
種類	Quasi-experimental design	Within-subject experimental design conducted in naturalistic settings
原典	Dunning, T. (2012). Natural Experiments in the Social Sciences: A Design-Based Approach. Cambridge University Press. ISBN: 978-1107698000	Senn, S. (2002). Cross-over Trials in Clinical Research (2nd ed.). John Wiley & Sons. ISBN: 978-0471496533
別名	within-unit natural experiment, reversal natural experiment, crossover quasi-experiment	within-subject field experiment, crossover field trial, repeated-measures field experiment, field crossover design
関連	5	5
概要	A crossover natural experiment exploits an externally imposed condition — a policy change, law, or environmental event — that exposes the same units (individuals, regions, firms) to both treatment and control states at different times. By observing each unit in multiple conditions, researchers use within-unit variation to estimate causal effects without researcher-controlled randomization, combining the internal validity advantage of crossover designs with the real-world relevance of natural experiments.	A crossover field experiment is a within-subject experimental design conducted outside the laboratory in naturalistic, real-world settings. Each participant or unit receives multiple treatments in a randomized sequence, separated by washout periods, allowing researchers to observe causal effects while each unit serves as its own control. This approach combines the internal validity of crossover designs with the ecological validity characteristic of field experimentation.