Consider a clinical investigation to assess the effectiveness of
a new drug designed to reduce repetitive behaviors in children
affected with autism. If the drug is effective, children will
exhibit fewer repetitive behaviors on treatment as compared to when
they are untreated. Repetitive behavior is scored on a scale of 0
to 100 and scores represent the percent of the observation time in
which the child is engaged in repetitive behavior. For example, a
score of 0 indicates that during the entire observation period the
child did not engage in repetitive behavior while a score of 100
indicates that the child was constantly engaged in repetitive
behavior. The data are shown below. Use the sign
test to determine if there is a statistically significant
improvement in repetitive behavior after one week of treatment.
Child:
1
2
3
4
5
6
7
8
Before:
85
70
40
65
80
75
55
20
After:
75
50
50
40
20
65
40
25