Due in part to strong objections from potential users, the result was a combination of a sample survey and a total census count. For communes with less than 6,000 inhabitants, a full census count including the use of the questionnaire was conducted. Moreover, seven communes with 6,000 or more inhabitants paid for a full census count. Altogether 282 communes had a full count, equivalent to 62.9 percent of all the commu-nes in the country. The total number of inha-bitants in these communes was less than 800,000, or 18.8 percent of the Norwegian population on November 3, 1990.
Results based on a sample of the population have a degree of uncertainty.
This is particularly true of small groups of the population, occupational groups with few members or data for small geographical regions. For a figure to be published it must be greater than a certain minimum value. As part of FoB90, SSB also employed a method of combining sample survey data and register data. Correction factors were created by comparing individual information gathered by the survey questionnaire with information from the register. This method generated figures for economic activity and industry with an uncertainty of almost one half compared to sample survey data alone.