Although Frances Heflin's name appears in the credits for playing Miss Harvey, those scenes were apparently cut from the finished product. Nowhere in the original airing of this episode does she appear.
Patty spells out the word 'frug' and explains it is the name of a dance. The frug was indeed a popular dance in the mid '60s that evolved from the chicken and the twist. It was characterized as a dance involving vigorous moves of arms, legs, and hips.
This is the sixth of 12 appearances Kitty Sullivan makes in the series as Sue Ellen. The character appears first in The Tycoons (1964), but is played by Susan Tyrrell.
David Butler, who directed this and Patty the Master Builder (1965) for the series, had a long and storied career as a director, beginning in 1927 with High School Hero (1927), a movie also about teenagers. His career, in fact, often crossed paths with young actors, Shirley Temple and a young Mickey Rooney among them.