Stats Sources Intern Training - The University Libraries

Statistical Sources

Numeracy or Quantitative Literacy

The ability to reason with numbers or statistical concepts
“Every year since 1950, the number of American children gunned down has doubled." From Damned Lies and Statistics: Untangling Numbers from the Media, Politicians, and Activists by Joel Best

Statistics versus Data

In general statistics are an aggregate of raw data. For example, sums, totals, averages, percentages are statistics. They provide a basis for comparison and argumentation.
Data is the underlying information from which statistics are formed.
Example: The total number of people who took our library survey is a statistic and the individual surveys themselves are the data.

Series

A category of statistics. Examples: "Female Population"; "Vehicles per 1000 people"; "Gross Domestic Savings (% of GDP)"

Base Period

A specific time measurement (usually a year, but it could also be a month or day), often used as the basis for a time series.

Time series

Measures of a single variable for consecutive years or time periods.
A time series is often based on a base year (i.e. a base period).
Example: The annual rainfall in Greensboro from 1990 to the present or the GDP for ten years.

Mean

The "average" in ordinary English. Also called the arithmetic mean (the sum of all the values divided by the total number of values.) For example, for this group of numbers:

4, 18, 20, 21, 23, 53, 103
the median is 34.57
(242 divided by 7)

Median

The number between the higher half of a population (or other type of sample) from the lower half. To find the median of a list of numbers, arrange all the numbers from lowest to highest, and pick the middle one. If there are an even number of observations, take the mean (average) of the two middle values. For example:

4, 18, 20, 21, 23, 53, 103
the median is 21

Raw Value

Index Value

Data adjusted to facilitate making comparisons. The numbers are presented relative to data from a base period (ex. data from 1999=100.00). The number look like percentages.

Per Capita

"For each head." The number or value per each person. Useful when comparing states or countries with varying populations. Most often used for comparing $ figures.

Actual Dollars

Not adjusted for cost of living index (commonly called inflation). In other words, the actual price of something when it was bought.

Constant Dollars

Adjusted for the cost of living index. A base period (ex. "1988 dollars") is used as the basis of the adjustment.

Covers 550 indicators for over 200 countries and 18 country groups, from 1960 to one year ago. Includes social, economic, financial, natural resource, and environmental data. Print version: Reference HC59.15 W656

Provides over 25,000 U.S. statistical data series on many topics, including population and demographics, economics, social indicators, voting and elections, geography, intellectual property, social services, and libraries.
Covers the U.S., states, counties, cities, and other Census-designated places (more than 30,000 places total).

Provides access to demographic statistics for states, cities, and counties of the United States using data from the 1990 Decennial Census, the ongoing American Community Survey, the 1997 Economic Census, and the 2000 Decennial Census.

Provides access to NC statistical data from the Census as well as other state and federal agencies.

For more information, contact: Lynda Kellam, Data Services & Government Information Librarian