Theodore Xenophon Barber (1927–2005) and David Smith Calverley (1937–2008) were psychologist

Psychologist

Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...

s who studied "hypnotic behavior". They measured how susceptible patients were to hypnotic induction

Hypnosis

Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...

. One result of their research was showing that the hypnotic induction was not superior to motivational instructions in producing a heightened state of suggestibility. The Barber Suggestibility Scale, a product of their research, measures hypnotic susceptibility

Hypnotic susceptibility

Hypnotic susceptibility measures how easily a person can be hypnotized. Several types of scales are used; however, the most common are the Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scales....

with or without the use of a hypnotic induction.