Question

Do TV shows with violence and sex impair memory for commercials? To answer this question, Iowa State researchers conducted a designed experiment in which 324 adults were randomly assigned to one of the three viewer groups of 108 participants each (Journal of Applied Psychology, June 2002). One group watched a TV program with a violent content rating (V), the second group viewed a show with a sex content rating (S), and the last group viewed a neutral TV program with neither a violent nor a sex rating (N). After viewing the program, each participant was scored on his or her recall of the brand names in the commercial messages, with scores ranging from 0 (no brand recalled) to 9 (all brand recalled). Identify each of the following elements:

a. Experimental units

b. Factor

c. Factor levels

d. Treatments

e. Response variable

f. Give null and alternative hypotheses

g. If p-value = .002, make a decision at .05 level of significance.

h. What is your conclusion?

i. Is there a treatment effect?

j. Is this a balanced design?

Answer 1

a. Experimental units - 324 adults

b. Factor - TV viewing groups

c. Factor levels -

i) a violent content rating (V), ii ) a sex content rating (S),

iii) neither a violent nor a sex rating

d. the treatments for the design are three

e. Response variable - mean recall scores of TV viewers

f. Give null and alternative hypotheses

Ho: mu1 =mu2 = mu3

Ha: not all means are equal

g. If p-value = .002, make a decision at .05 level of significance.

p-value < alpha

we reject the null hypothesis

h)

we conclude that there is significant difference between three groups