**Administrative Data:** Administrative data reflect the administration of programs, policies or services, not direct population data.

**Aggregate Data:** Aggregate data present the total number of occurrences within a geographic area, not individual data.

**Cohort:** A cohort is a well-defined group of people who have had a common experience. For example, a group of people born during a particular period or year is called a birth cohort.

**Denominator:** The denominator is the lower portion of a fraction used to calculate a rate or ratio. In a rate, the denominator is usually the population at risk.

**Ethnicity:** A term which represents social groups with a shared history, sense of identity, geography and cultural roots which may occur despite racial difference.

**Hispanic:** Hispanic refers to persons who identify themselves as Mexican, Puerto Rican, Cuban, Central or South American, or of other Hispanic origin or descent. In US Census data, persons of Hispanic origin may be of any race; thus, they are included in both the white and black population groups.

**Indirect Measures:** Community indicators are not necessarily direct measures of the population's behavior but may be measures of the community service systems. Policy shifts, resource fluctuations, degree of centralization and standardization, local reporting practices and local service delivery differences affect indicator data. Other factors in the community-including availability, affordability and quality of service-may also affect indicator data. Local qualitative information regarding the role of the indicator in the context of its service setting must be obtained and applied when interpreting the results of indicator-based studies. For example, the youth arrest rate for driving while intoxicated is a direct measure of a law enforcement response to youth alcohol and other drug (AOD) use and is an indirect measure of your AOD use in the population.

**Maximum:** The maximum identifies the largest value within the range of percents or rates.

**Mean:** The mean, a measure of central tendency, is the average. To calculate the mean add all of the values for each region and divide by the total number of regions.

**Median:** The median, a measure of central tendency, is the value of the middle item when the data are arranged from lowest to highest. Since New York State has an even number of counties (62), the median is computed by averaging the two middle observations, point 31 and 32. If New York City Counties' data are not available, the median is the middle observation, point 29 of the range. While the median is not sensitive to outliers and guarantees that 50 percent of the values fall on either side of the value, it may not be representative of all county percents or rates.

**Metadata:** Metadata provides information about the content, quality, condition, and other characteristics of data.

**Minimum:** The minimum identifies the smallest value within the range of percents or rates.

**Number:** The number is the count of occurrences within a defined geographic area during a specified period of time. Numbers are used to determine the size of an occurrence in a particular location. Numbers, however, do not take the size of the population who could experience the occurrence into account. Therefore, numbers cannot show the probability of this occurring in the population. While numbers can compare the size of an occurrence within the same population group, numbers generally should not be used for comparisons, especially when comparison groups have differing population size or composition.

**Numerator:** The numerator is the upper portion of a fraction that reflects the number of events within a geographic area and designated time.

**Percent:** A percent reflects the occurrence per 100 of the population and can be expressed in other formats (e.g., 25% can also be expressed as 25 in 100, one quarter, or 1 in 4). To compute a percent, divide the number of occurrences by the total population who could experience the occurrence and multiply by 100.

**Percent Change:** By accessing base and current period data, the user is able to determine the percent of change between two periods of time. To calculate a percent change, find the difference between the current year rate and base year rate [subtract the base rate from the current rate], then divide the difference by the base year and multiply by a standardized multiplier (100 is used as the multiplier to present the change as a percent). The difference between the rates can show an increase (positive number) or decrease (negative number) and depending on the indicator, can depict a negative or positive change.

**Percent Difference:** By accessing base and current period data, the user is able to determine the percent of change between two periods of time. To calculate a percent difference, subtract the base rate from the current year. The difference between the rates can show an increase (positive number) or decrease (negative number) and depending on the indicator, can depict a negative or positive difference.

**Rate:** A rate is a measure of some event, disease, or condition in relation to a unit of population, along with some specification of time. Rates provide a standardized means of comparing the prevalence of an indicator over time and across different geographical areas (e.g., counties, states). Therefore, rates provide an excellent way to measure progress towards meeting goals and standards. To compute a rate, first divide the number of occurrences (the numerator) by the total population who could experience the occurrence (the denominator), then multiply by a standardizing multiplier. Indicators in this data book utilize the following multipliers: 1,000; 10,000; or 100,000 and are reported as per 1,000; per 10,000; and per 100,000, respectively. However, rates calculated in this manner are called crude rates and have not taken into consideration possible differences in population characteristics necessary for comparisons.

**Rate Ratio:** Rate ratios are used to compare rates, e.g., comparing rates between different age groups, different sexes, different time periods and different causes of an event. To compute a rate ratio, divide a rate by the rate you would like to compare.

**Sample Data:** A sample is a subset of people in a particular population.

**Time Period:** The timeframe (e.g., base year, current year) for the majority of indicators in KWIC is the annual calendar year, January 1 through December 31. However, there are two exceptions: (1) the State Education Department generally collects data for the school year, July 1 through June 30 and (2) the rates for indicators with relatively rare events in many counties are presented as three-year averages. Three-year averaging is necessary to improve the reliability (or stability) of the data.

**Young Adult:** A Young Adult is a person aged 16 to 21 years old.