Information Impermanence

As you search for information, save your sources, particularly datasets and government publications. Note the date you were last able to access a source in case it isn’t available later. Check the Internet Archive’s Wayback Machine and other repositories for removed data sources or websites.

Citation managers can help you manage the information you save about your sources. You can reference and cite information that is no longer available where you found it. For these citations, include a last accessed date.

Having trouble finding data or a source? Talk with your subject librarian.

Searching for Data

When searching for government data that may have been removed, search in this order:

  1. Data.gov - Confirm the data is not active or relocated.
  2. Internet Archive Wayback Machine - Locate past versions of web pages.
  3. Data Rescue Project's Data Rescue Tracker - Check for rescued datasets.
  4. Other Archives - Consult relevant domain-specific or institutional repositories. Some of these can be found in this guide. If you are having difficulty finding a data set, please contact your subject librarian.

Not sure what dataset you need? Here are some search tips. Your subject librarian can also help you with this.

For help evaluating data quality, the Data Quality Literacy Guidebook is a good place to start.

Preserving U.S. Government Data

For more information about changes to U.S. government data and webpages, please see our Preserving U.S. Government Data guide.