A new set of cognitive training modules called ONTRAC was developed to help children with attention deficit hyperactivity disorder (ADHD) to improve focus and to more easily dismiss distractions (“Training Sensory Signal-to-Noise Resolution in Children with ADHD in a Global Mental Health Setting,” Translational Psychiatry, April 12, 2016, nature.com/tp/journal/v6/n4/full/tp201645a.html, retrieved May 23, 2017). Eighteen children with ADHD were randomly assigned to one of two treatment groups. One group of 11 children received the ONTRAC treatment and another group of 7 children received a control treatment.

Values for 1-year improvement in ADHD Severity Score consistent with graphs and summary statistics in the research article appear in the following table.

ONTRAC ....................... Control
11.0 .................................. 4.3
8.8 .................................... 3.8
12.1 .................................. 8.5
10.9 .................................. 4.7
8.0 .................................... 1.5
8.2 .................................... 7.7
11.9 .................................. 8.0
11.1
11.8
10.8
12.0

a. Explain why it is wise to be wary of using the two-sample t methods to analyze the data from this study.

b. Do these data support the claim that the mean 1-year improvement in ADHD Severity Score for the ONTRAC treatment is different from the mean 1-year improvement in ADHD Severity Score for the control treatment? Use a randomization test with significance level 0.05 to answer this question. You can make use of the Shinyapps in the collection at statistics.cengage.com  /PSO6e/Apps.html.