What Is Public Data?

Most people can agree on a definition of the term "data." Data consists of facts -- items of information you can use to make decisions. But arguments invariably develop as to whether data is public, personal or proprietary. To understand what public data is requires that you first consider it within its categorical context.

Categories of Data

Proprietary data is owned by its generator. A corporation's study of conference attendance by its employees constitutes proprietary data. You cannot legally access such data unless the company originating the data chooses to let you do so.
Personal data is focused on a particular individual. John Smith's personal cell phone records are personal data, which John can usually expect to be exempt from public access. Agreeing with John in this expectation are civil liberty groups like the Electronic Frontier Foundation, the Center for Democracy and Technology and the American Civil Liberties Union. These organizations help prevent you from being able to retrieve John's personal data.
Public data consists of any non-proprietary data generated without reference to specific individuals. Since much of this data consist of information compiled by government agencies like the Census Bureau or the Social Security Administration, public data is often equated with government data. Generally, you are legally entitled to access public data. Sensitive data like national security information, however, remains exempt.

Access to Public Data

Laws such as the Freedom of Information Act have broadened your access to data generated by governmental agencies that is neither personal nor sensitive. Despite your legal access to public data, the format of this data often limits its use.

Data.gov

The May 21, 2009 debut of the Data.gov website provides an example of one product of the Open Government Initiative. Using the Data.gov home page, you can retrieve public data in raw form by agency, category, keyword, or format searches. You can also access data extraction tools and widgets from this site.

Private Sector Data Access Initiatives

President Barack Obama's Open Government Initiative, designed to make the federal government more transparent and accessible, has influenced the private sector: April 28, 2009 saw the launch of two projects designed to increase your access to public data -- Google Public Data and the Wolfram Alpha Computational Knowledge Engine.

Google Public Data

Google Public Data allows you to create a chart based on comparative figures for population data from the U.S. Census Bureau or unemployment rates from the U.S. Bureau of Labor Statistics. Just type the words "population" or "unemployment rate" followed by the name of a U.S. state into the Google search box and click on the chart image that you retrieve. You will be taken to an interactive page where you can graph comparative statistics for any U.S. county and state combination.

Wolfram Alpha Computational Knowledge Engine

Stephen Wolfram claims that the goal of his Wolfram Alpha Computational Knowledge Engine is "to provide a single source that can be relied on by everyone for definitive answers to factual queries." Wolfram Alpha is not, as is Google Public Data, a search engine. Instead, it manipulates public data to answer questions that you ask. Typing in "Who was president of the United States in 1949" at Wolframalpha.com will show you the extent of data even a simple query can generate.

Future of Access Initiatives

These public and private sector initiatives are still in their infancy. The goal of achieving full access to public data will not be quickly achieved, but it is well worth the wait.