The 1970 census, like all other censuses which are separately documented, was designed to gather population and housing data. Population data include number of inhabitants, age, sex, marital status, citizenship, mother tongue, highest grade completed, literacy, ability to speak Pilipino, Spanish and/or English, religion, gainful and non-gainful occupation, vocational or technical skill, major and minor industry, class of worker, fertility and migration. Housing items cover type of building, type of occupancy, construction materials of roof and outer walls, year built, dwelling unit characteristics, type of tenure, kind of lighting facilities, source of water supply, type of toilet facilities, type of cooking fuel and ownership of household appliances. Definition of terms and concepts can be found in the explanatory text of the final report.
The enumeration unit used was the household. Personal interviews of the head or any responsible member of the household were conducted using PH Census Form No. 2, 2A or 5-B. A combination of complete enumeration and sampling was employed. Items relating to the population count and personal characteristics were asked of all households while 5% (or every 20th household) were asked additional questions. The latter procedure was also true for institutional populations. A simple two-stage sampling design was utilized in the post-enumeration survey which was conducted after the main survey to measure coverage and content errors. No additional codes were adopted for documentation purposes.