This interferance included choosing topics that the contestants were good at, answers to upcoming questions and even stage directions of how to act on camera. In the 1950s, it was common practice for game shows and other shows to be sponsored solely by one company; so much so to even have the company's name in the title of the show. Examples included Sylvania's "Beat the Clock", or Geritol's "Twenty-One". It was emperically determined by these companies and the networks that fixing the outcome of a game show made it more likely to be watched for its dramatic value, thus increasing the advertising a sponsored company received on every show.
The most notorious participants in this deception were Charles Van Doren and Herb Stempel who were leading competitors on the show, Twenty One. Both were heavily coached by the show's producers, but Stempel blew the whistle when he was pressured to deliberately lose in favor of Van Doren.
The impact of this scandal led to a specific federal law prohibiting fixing quiz shows. Contestents like Van Doren found their reputations were ruined and quiz shows lost much of their remaining presence on prime time American television for decades. In addition, the major television networks took a greater hand in creative production to avoid similar problems in the future. This even extended so far as to demand changes to unrelated television series like demanding that the premise of the dramatic series, Mr. Lucky be changed from a riverboat casino to a restaurant to avoid the idea of games on prime time TV. The scandal also marked an end to widespread naming of television shows by their sponsors. Future game shows like The Price is Right or Let's Make a Deal were not sponsored by any one company.
This scandal is dramatized in the feature film Quiz Show directed by Robert Redford.