Any printed sources (both paper and digital) that we quote, link to, use as background information for, or otherwise reference in our fact checks are listed in the Sources section at the foot of each fact check article. (This section is now an expandable link: readers can click on the word “Sources” to expand or collapse the source listings.)
In cases where we have contacted individuals or organizations by e-mail or telephone for comment, that information is noted within the text of articles and is not usually listed separately in the Sources section.
Media embedded within the body of our articles for illustrative or informational purposes, such as YouTube videos and social media posts, are also not separately listed in the Sources section.
Our research into various topics generally begins with (whenever possible) attempting to contact the source of the claim for elaboration and supporting information. We also attempt to contact individuals and organizations who would be knowledgeable about, or have relevant expertise in, the subject at hand, as well as searching out printed information (news articles, scientific and medical journal articles, books, interview transcripts, statistical sources) with bearing on the topic.
We attempt to use non-partisan information and data sources (e.g., peer-reviewed journals, government agency statistics) as much as possible, and to alert readers that information and data from sources such as political advocacy organizations and partisan think tanks should be regarded with skepticism.