In the 1983 census a change was made in the method of collecting data from the residents. Similarly to previous censuses, this time too the enumeration was conducted in two stages:
In the first stage the residents received questionnaires of two types, for filling in themselves: a short questionnaire, which included a small number of basic demographic questions and was distributed to 80% of all households; and an extended questionnaire, which was distributed to the remaining 20% of households. The extended questionnaire included, in addition to basic demographic questions, a variety of detailed questions on social, economic and demographic subjects.
In the second stage the enumerators returned to the residents' homes and collected the questionnaires. At this stage they also completed, with the help of the residents, anything missing in the answers.
This method made it possible to concentrate on enumerating all the households in the first stage (the stage of distributing the questionnaires), and concentrate on problems relating to filling out the questionnaires in the second stage (the stage of collecting the questionnaires). The addition of a short questionnaire for the residents to fill out alone (in previous censuses they only filled out the extended questionnaire by themselves) reduced the burden on the enumerators to a great degree, and made it possible for them to concentrate on correcting errors and completing missing material.
The change made in the enumeration stages reduced greatly the extent of the "non-responses" (to questions) in the extended questionnaires, and thus also improved the coverage and quality of information obtained, compared with the previous censuses
