Question

During a 2-month trial period, an accounting firm institutes an exercise break for its employees to see if this will improve their sense of well-being. A sample of 61 employees are randomly chosen from the list of all employees at the firm . Consider two possible study designs:

Study Design 1
Selected workers are randomly assigned into two groups: one group is instructed to take exercise breaks during the work day; the other groups continues working without exercise breaks as usual. At the end of the study, both groups are asked to rate their sense of well-being.
This is classified as an independent groups design.

Study Design 2
All selected workers experience both treatments: working with exercise breaks for one month and working out without exercise breaks for one month. The order of the treatments is randomized. Workers are asked to rate their sense of well-being at the end of each month.
This is classified as a paired design.

1. If exercise breaks really do improve a worker's sense of well-being, which of these designs would you expect to provide stronger evidence of that effect?

2. What is the reasoning for answering as paired design? Why does paired design provide stronger evidence?

Answer 1

1) in my opinion paired design would provide stronger opinion.

2) the reason for choosing paired design is that in this type of experiment all the employees will experience both type of situations, working with exercise break and working without exercise break, so we will get more precise and accurate knowledge that in which condition their sense of well being was better.

• The problem study design 1 is that some of the differences might be due to the fact that the employees from the 2 groups are just different (sex, height, age, IQ, etc.)

• Study design 2 would not have this issue since we are using the same group of employees for both conditions and comparing the sense of well being of the same employee. The assessment would be more accurate.