United States: how to read November 3 election results

Media projections of winners can come before counting is complete. Reuters explains that they use reported votes and estimates of the ballots remaining. [2]

Projection and certification

The Election Assistance Commission notes that election-night results are unofficial. Only election authorities establish official results, following the checks and certification required in their jurisdiction. [1]

Sometimes the data are shared

According to Reuters, many outlets use vote counts from AP or Decision Desk HQ. Several announcements based on the same provider therefore do not represent several independent counts. [2]

Why counting continues

Officials reconcile ballots and voter records during the canvass. Procedures and deadlines differ among states; a media projection does not replace that work. [1]