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Carrying weapons at school: Notes & Sources

Source: Healthy Youth Survey. Every 2 years, Washington public school students in 6th, 8th, 10th, and 12th grades answer questions about safety and violence, physical activity and diet, alcohol, tobacco and other drug use, and related risk and protective factors. To learn more about the survey, please go to

Indicator Definition 

Numerator: Students who responded "Yes" to the question "During the past 30 days, did you carry a weapon such as a gun, knife, or club on school property?”

Denominator: All students who answered the question.

The sexual orientation rates for this indicator includes data for 2016 only

Other Notes

Confidence interval (also called "error bar") 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 statistically significant (meaning that chance or random variation is unlikely to explain the difference).   

King County regions: The geographic boundaries of the four King County sub-regions (North, Seattle, East, and South) are defined by the aggregation of 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:  Hispanic, Black, American Indian/Alaska Native (AIAN), Asian, Native Hawaiian/Pacific Islander (NHPI), White, and Multiple Race (Multiple). Persons of Hispanic ethnicity can be of any race and 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:  When the frequency of an event varies widely from year to year, rates are sometimes aggregated into averages – often in 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. Statistical tests comparing data points with overlapping times are not appropriate.