ይበልጥ በአጠቃላይ, የተፈጥሮ ሙከራዎች አንድ ጥሩ መግቢያ ነው Dunning (2012), እና Rosenbaum (2002), Rosenbaum (2009), እና Shadish, Cook, and Campbell (2001) ሙከራዎች ያለ በሲጋራና ውጤት ለመገመት ጥሩ ሐሳቦች ያቀርባሉ.
Kawirikawiri, kulongosola bwino kwa masoka achilengedwe kumaperekedwa ndi Dunning (2012), pamene Rosenbaum (2002), (???), ndi Shadish, Cook, and Campbell (2001) amapereka malingaliro abwino onena za kuyeretsa zotsatira popanda kuyesa.