Complex sentence: Ernest Ropiequet "Jack" Hilgard (July 25,1904--October 22,2001) was an American psychologist, professor at Stanford university, who became famous in the 1950s for his research on hypnosis, especially with regard to pain control.
Split into simpler sentences: Ernest Ropiequet "Jack" Hilgard (July 25,1904--October 22,2001) was an American psychologist and professor at Stanford University. He became famous in the 1950s for his research on hypnosis, especially with regard to pain control.