Trivia: Kimberly's school is the same school from the Facts of Life. It even has the same classmates and Kimberly shows up sometimes.
Trivia: Robin Williams improvised so much of his dialogue that the show's writers finally stopped writing his lines and just left blank space in the scripts with cues and prompts for him.
Suggested correction: I'm researching Mork and Mindy for a feature. Contemporary interviews say Robin Williams was given leeway to improvise but this was only about 5% of an episode. These were probably done in rehearsals and incorporated into the final scripts. It would be impossible to film each episode if Williams wholly improvised as the cameras wouldn't know if he was going to hit his marks (i.e. where any actor needs to be so is in frame) and for other cast to react to. So partly true but not the whole story.
Trivia: The role of Louie's Mother is played by Danny DeVito's real-life mother, Julia.
Trivia: The show was videotaped instead of filmed because it was cheaper to obtain the rights to rock songs for a taped show.