Public or Private Data?

Many of the free web-based tools in this book require that your publicly share your data. Check each tool and decide whether it is appropriate for your data, which may have some privacy restrictions.

In some cases, individual data privacy is protected by law, but a government agency may aggregate (sort into larger groups) or anonymize (remove personally identifiable details) data to make it public. For example:

• Individual-level census data is private for about 70 years, but the US Census Bureau publicly releases anonymous data for aggregated areas (such as census blocks, tracts, towns, etc.)
• Patient-level health records are private, but public health officials share town- and county-level health data.
• Student-level education data is private, but school districts and state agencies publicly share grade-level and school-level data.

In other cases, individual data is not private. For example:

• When individuals contribute to political campaigns, most US and state laws require that the donor name, address, and amount is public data.
• When an individual buys home in Connecticut, the owner's name, address, purchase amount, and other details about the home are public data.