That is the reason why the participation of each randomly selected respondent is very important from the survey viewpoint. Such personal identification data as name and address were asked only in order to contact the respondents by the questioners.
Sel põhjusel oli iga küsitlusse sattunud vastaja osalemine uuringu seisukohalt väga tähtis. Selliseid isikuandmeid nagu nimi ja aadress oli vaja ainult selleks, et küsitlejad saaksid küsitletavatega kontakti võtta.