What is the doctrine of joint work?

The leading American authority interpreting "joint work" is Childress v. Taylor, supra. In that case, the plaintiff playwright alleged infringement of copyright in a play she wrote. The defendant actress claimed to be a joint author of the play by, inter alia, providing research material to the plaintiff, discussing with the plaintiff the inclusion of certain general scenes and characters in the play, and speaking with the plaintiff on a regular basis about the progress of the play. The court affirmed the trial judge’s decision that the plaintiff was the sole author of the play.