Scenario: At the first meeting of an American History class for new freshmen, the professor identifies 10 students who appear to be the most anxious individuals in the class. Based on their observed behaviors, the professor rates each student's anxiety level on a 10-point scale. After class, the 10 students are approached and offered an opportunity to participate in a 2-week massage therapy program free of charge. All 10 students accept the offer. At the first class meeting after the massage program, the professor again observes the 10 students and rates each individual's level of anxiety. The results indicate a significant decrease in anxiety following the 2-week massage therapy program. The professor would like to conclude that the massage program caused a reduction in anxiety.
A.Briefly describe how history might provide an alternative explanation for the reduction in anxiety.
B. Briefly describe how instrumentation might provide an alternative explanation for the reduction in anxiety.