Dabalataan, iddatteessuun mit-carraa yeroo baay’inni jamaa hinbeekamne yookiin tokkoo tokkoon addaan baasuufis rakkisaa ta’u kan fayyadamnu ta’uu Kumar (2005:177) akkanatti dhiheessa, “Non probability sampling designs are used when the number of elements in a population is either unknown or can not be individually identified.
