# How did a UNIVAC predict the results of the 1952 U.S. Presidential election?

The first computer prediction of a U.S. Presidential election was by a UNIVAC I computer used by CBS News on election night 1952. At 9:15 pm, with only 3.4 million of the eventual 61.8 million popular votes counted, the UNIVAC predicted 43 states and 438 electoral college votes for Dwight Eisenhower, and 5 states and 93 electoral votes for Adlai Stevenson. The actual results were 39 states and 442 electoral votes for Eisenhower. The popular vote was also within 3.5%. It proved to be a success for both UNIVAC and CBS.

What inputs and algorithms were used by the UNIVAC to predict the election? Was this merely a ratio of the votes counted at the time, or was there a more sophisticated mathematical model?

• There's a wide range of potential statistical algorithms, from using the outcome of the last elections as a baseline, to more finer grained methods that identify important voting districts and weight them. It's probably impossible to say which methods they used without seeing the source code, but as computer usage was quite maths heavy at that time, it's virtually sure they used as much statistics as the UNIVAC was able to handle. – dirkt Nov 3 '20 at 4:44