To the degree possible, they attempt to collect data for the system in such a way that contribution from all variables can be determined, and where the effects of variation in certain variables remain approximately constant so that the effects of other variables can be discerned.
Sadohnyané, ipun mautsaha mupulang data mangda sistem kadi punika prasida nagingin makasami variabel prasida katentuang, raris ring dija ja efek variasi ring silih tunggil variabel prasida nampek ring konstan sané ngawinang efek variabel tiosan prasida kacingakin.