Glossary of terms

Below are explanations of commonly used terms on Communities Count that may require some additional clarification. We hope that these will be helpful in understanding and interpreting data on the site. If you are not finding what you are looking for or have other questions, please contact us at

Term Definition
Cities and Neighborhoods King County Health Reporting Areas were created to align with city and neighborhood boundaries in King County, so they are also called “cities and neighborhoods” in many of our materials. Where possible, they correspond to neighborhoods within large cities, and delineate unincorporated areas of King County. They were designed to help cities and planners as they consider issues related to local health status or healthy policy. They are used whenever we have sufficient sample size to present the data at this geographic level.
Confidence Interval Also known as the error bar, the confidence interval is the range of values that includes the true value 95% of the time. If the confidence intervals of two groups do not overlap, the difference between groups is considered statistically significant (meaning that chance or random variation is unlikely to explain the difference).
Family household The U.S. Census Bureau defines a family household as a household in which at least 1 person is related to the householder by birth, marriage, or adoption. Since 2013, the U.S. Census has included same sex married couples in its definition of family. The U.S. Census excludes unmarried opposite-sex partners and households with grandparents and grandchildren (but not parents) from its definition of family households.
Federal Poverty Guidelines Federal Poverty Guidelines are issued by the U.S. Department of Health and Human Services and are used to determine financial eligibility for various federal, state, and local assistance programs. The guidelines are based on the U.S. Census Bureau’s federal poverty thresholds. For a family of 4, the federal poverty guideline was $25,750 in 2019. For more information about the 2019 Guidelines, please see:
King County Regions The geographic boundaries of the four King County sub-regions (North, Seattle, East, and South) are defined by combining cities and neighborhoods.
Race/Ethnicity Federal standards mandate that race and ethnicity (Hispanic origin) are distinct concepts requiring 2 separate questions when collecting data from an individual. "Hispanic origin" is meant to capture the heritage, nationality group, lineage, or country of birth of an individual (or his/her parents) before arriving in the United States. Persons of Hispanic ethnicity can be of any race. Communities Count's terms for racial/ethnic groups are derived from those used by the U.S Census Bureau in 2010. Communities Count terms include: Hispanic, Non-Hispanic, Black, American Indian/Alaska Native (AIAN), Asian, Native Hawaiian/Pacific Islander (NHPI), White, and Multiple Race (Multiple). Persons of Hispanic ethnicity are included in other racial categories. Racial/ethnic groups are sometimes combined when sample sizes are too small for valid statistical comparisons of more discrete groups.
Rolling averages In our visualizations, when the frequency of an event varies widely from year to year, rates are sometimes shown as averages – often over 3-year intervals – to smooth out the peaks and valleys of the yearly data. For example, for events occurring from 2001 to 2010, rates may be graphed as three-year rolling averages: 2001-2003, 2002-2004…2008-2010. Adjacent data points will contain overlapping years of data.