Jonathan Ke Quan was added to the cast in the fifth season because the producers realized that it was unusual that there were no Asian-Americans in a class for gifted students.
Eric Mardian: [in response to Viki trying to find her birth mother]
We're here to help you babe. We're looking for a tall blonde, killer body, killer legs, killer smile, a little spacey, but hot.
Stacy Jenel Smith reported in her "Ask Stacy" column that Hesseman requested to be released from the show. He had been openly unhappy with the show for years, often speaking badly of it in interviews. Smith said cast and crew of the show reported that Hesseman's ill feelings for the show cast a pall on the production.