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.
Die gbogbo, kan ti o dara ifihan si adayeba adanwo ni Dunning (2012), ati Rosenbaum (2002), Rosenbaum (2009), ati Shadish, Cook, and Campbell (2001) pese ti o dara ero nipa esitimeti ifẹsẹmulẹ ipa lai adanwo.