Comparison between 100% and Sample Data

Questions on the short form are referred to as “100-percent” questions because they were asked of the entire population. Census products based on 100-percent data are Redistricting Summary File (Public Law 94-171), Summary File 1 (SF1), Summary File 2 (SF2), and one-page Demographic Profiles..

The “sample” data, which is the backbone of SF3, was collected from an average of about one-in-five Alaska households who were asked to complete the long form questionnaire. (In some census tracts the ratio was one-in-eight, and in rural Alaska as many as one-in-two households received the long form.) This data is called sample data because it was collected from a sample of the population.

The long form asked the same 100-percent questions as the short form but included additional questions about topics such as education, employment, income, ancestry, and homeowner costs. It is important to note that due to sample weighting, there may be differences between counts shown in the 100-percent SF1 and SF2 and the totals shown in the sample based SF3.

To see how 100% and sample population data compare for all 349 Alaska's places, see the excel file.

The table below shows numeric and percent differences by place size. In general, the percent of difference is larger for smaller places.

Comparison of 100% vs. Sample Population Totals

Size of Place Number of Places Percent Difference Average Difference Average % Difference
0 to .9 1 to 4.9 5 to 9.9 10 to 24.9 25 to 49.9 50 to 99.9 100 and over
Places less than 500 239 22 46 60 74 19 15 3 15 15.2
Places 501-2499 77 21 39 14 3       27 2.6
Places 2500-9999 27 20 7           36 0.5
Places 10,000 or more 4 4             21 0.0
All Places 347 67 92 74 77 19 15 3 19 11.1