The Patty Duke Show, as well as Liv and Maddie, are TV series starring look-alike persons, played by one person. Producers of "Liv and Maddie" said they were inspired by Duke's show and long hoped she'd appear on theirs. Cameron studied all three seasons of "The Patty Duke Show" to prepare for her roles as twins, and said she cried when she learned she'd be working with Duke.
Patty Duke is appearing on Liv and Maddie as their Grandma Janice, who also has a twins. It's possible she plays both of them at the same time. Being the Grandma refers to the fact, that The Patty Duke Show was Liv and Maddies "Grandma".
- Both identicals are played by one Person (Patty Duke / Dove Cameron)
- Each actress gave name to one identical (Patty Duke - Patty Lane / Dove Olivia Cameron - Olivia 'Liv' Rooney)
- There are "Back-Doubles" you can see in both Series (Rita McLaughin as Patty Lane / Cathy Lane's back and e.g. Emmy as Liv 2)
- Each show's girls look-alike, but they're styles, attitudes and tastes are completly different
- At the beginning of each show, one half of the identicals return back home: Liv from Hollywood, Cathy Lane returns to her uncle's family since her father's a glob-trotting journalist
- The Patty Duke Show was the first, Liv and Maddie the second TV series about one person playing two
- Dove Cameron's playing identical twins, while Patty Duke's playing identical cousins
- While Liv and Maddie are twins, Cathy Lane and Patty Lane are pratically half siblings, since they're fathers are identical twins
- The Patty Duke Show uses split screen to make Patty Duke appear as identical cousins
- While Dove Cameron can't chose between Liv or Maddie, Patty Duke said that she prefered Cathy. "Patty was very embarrasing for her"