Editing Robot (Doctor Who) (section)

=== Casting ===
[[File:Tom Baker cropped.jpg|thumb|left|200px|Tom Baker made his debut as the fourth incarnation of the Doctor in ''Robot''.]]
It was known beforehand that Jon Pertwee would be leaving his role as the Third Doctor and that a new [[Fourth Doctor]] would need to be cast for the part.<ref name="Sladen 2012" /> [[Tom Baker]] had previously had major parts in several films, including ''[[Nicholas and Alexandra]]'' (1971) and ''[[The Vault of Horror (film)|The Vault of Horror]]'' (1973), but had found himself unemployed as an actor and working in construction at the time.<ref name="Westthorp 2008" /><ref name="Westthorp 2010" /> He had written to Bill Slater, the Head of Serials at the BBC, asking for work.<ref name="Westthorp 2010" /> Slater suggested Baker to ''Doctor Who'' producer [[Barry Letts]], who had been looking to fill the part.<ref name="Westthorp 2008" /><ref name="Westthorp 2010" /> Letts saw Baker's work in ''[[The Golden Voyage of Sinbad]]'' (1973) and hired him.<ref name="Rawson-Jones 2009" /> Baker would continue in his role as the Doctor for seven seasons, longer than any other actor.<ref name="AudioFile staff 2009" />

[[Nicholas Courtney]] and [[John Levene]] reprised their roles as [[Brigadier Lethbridge-Stewart]] and [[Sergeant Benton]] respectively.<ref name="Braxton 2010" /> Levene had started his role with the [[Second Doctor]] story ''[[The Invasion (Doctor Who)|The Invasion]]'' (1968) as a member of the military organisation [[UNIT]] (the United Nations Intelligence Taskforce). Courtney started earlier in the same year in ''[[The Web of Fear]]'', with his character's rank being a colonel. They, along with Sladen, would be the transition cast to carry through from the Third Doctor to the Fourth Doctor, though this would be the only UNIT story for the twelfth season. The Earth-based stories involving UNIT, which had regularly featured in the Third Doctor's period, were introduced partly as an effort to reduce production costs when the series moved into colour by [[Peter Bryant]] and [[Derrick Sherwin]], the show's previous producer and script editor, as well as to base the series more on ''[[The Quatermass Experiment]]'' (1953).

Edward Burnham portrays Professor Kettlewell, the wild-haired, bespectacled [[boffin]] who creates the titular K1 robot.<ref name="Braxton 2010" /> Along with Courtney and Levene, Burnham had also appeared in ''The Invasion'', where he played another scientist, Professor Watkins. The part of the K1 robot is played by [[Michael Kilgarriff]]<ref name="Braxton 2010" /> who had played another robotic part in ''[[The Tomb of the Cybermen]]'' (1967), the [[Cyberman|Cyberman Controller]]. [[Patricia Maynard]] is cast in the part of Miss Hilda Winters, the director of the National Institute for Advanced Scientific Research.<ref name="Braxton 2010" /> Miss Winters' assistant, Arnold Jellicoe, is played by Alec Linstead.<ref name="Braxton 2010" /> Linstead had played the part of Sergeant Osgood—a member of the technical staff at UNIT—in ''[[The Dæmons]]'' (1971).