Almost all of the data we compile is taken directly from the websites of local or state/territory public health authorities. Where data is missing from these websites, we sometimes supplement available numbers with information from official press conferences with governors or public health authorities.
Individual state/territory data pages such as Wyoming’s, all of which are accessible from our main data page, include links at the top of the page to our data sources for each state and (from March 14 forward) timestamped snapshots of data sources. We discuss changes and ambiguities in data sources in the public notes for every state on our main data page and on each state’s individual data page.
The COVID Tracking Project can’t offer official guidance to state health departments or compel states to report missing data. We’ve built a state grading system so that state governments and their constituents can see who’s doing well and who is underperforming. We’ve built a volunteer outreach team who are in contact with authorities in every state and territory. But in the end, all we can do is ask for better and more complete data—and then ask for it again. If you’d like to see better data, please contact your governor.