In Alaska, West Virginia and other mostly rural states, census takers relied more on the word of neighbors, landlords and others for information about a home's residents.
In New Jersey, New York and other more densely populated states in the Mid-Atlantic region, they were more likely to come away from a household lacking basic information on race, sex and ethnic background.
An Associated Press review of the first data-quality measurements released by the U.S. Census Bureau last month shows some early patterns that may point to red flags in the data that could emerge when more detailed numbers from the 2020 census are released in August.