Complex sentence: Other game shows before this were "test episodes" for experimental purposes, one of which was "Truth or Consequences" in the same year while a show called "Spelling Bee" was broadcast on the BBC in 1938.
Split into simpler sentences: Other game shows before this were "test episodes" for experimental purposes. One of these was "Truth or Consequences" in the same year, while a show called "Spelling Bee" was broadcast on the BBC in 1938.