Hypnosis and Pain. In the paper "An Analysis of Factors That Contribute to the Efficacy of Hypnotic Analgesia" (Journal of Abnormal Psychology, Vol. 96, No. 1, pp. 46-51), D. Price and J. Barber examined the effects of hypnosis on pain. They measured response to pain using a visual analogue scale (VAS), in centimeters, where higher VAS indicates greater pain. VAS sensory ratings were made before and after hypnosis on each of 16 subjects. A hypothesis test is to be performed to decide whether, on average, hypnosis reduces pain.

a. identify the variable.

b. identify the two populations:

c. identify the pairs

d. identify the paired-diffenence variable.

e. determine the null and allernative hypotheses.

f. classify the hypothesis test as nwo tailed, left tailed, or right tailed.

Hypnosis and Pain. In the paper "An Analysis of Factors That Contribute to the Efficacy of Hypnotic Analgesia" (Journal of Abnormal Psychology, Vol. 96, No. 1, pp. 46-51), D. Price and J. Barber examined the effects of hypnosis on pain. They measured response to pain using a visual analogue scale (VAS), in centimeters, where higher VAS indicates greater pain. VAS sensory ratings were made before and after hypnosis on each of 16 subjects. A hypothesis test is to be performed to decide whether, on average, hypnosis reduces pain.

Here the variable of interest is visual analogue scale (VAS).

Same population is measured before and after the hypnosis.

VAS of people before and after of a particular person.

The difference between VAS of a pair of before and after of a particular person.

(e) Null hypothesis,

$H_0$:On average, hypnosis does not reduce pain.

$H_0:{\mu }_1={\mu }_2$(Symbolically)

Alternative hypothesis,

$H_a:$On average, hypnosis reduces pain.

$H_a:{\mu }_1>{\mu }_2$(Symbolically)

Here the alternative hypothesis contains the > symbol, it represents the test is right tailed test.