Question

For each of the statistical studies described indicate whether the study is an observational study or an experiment. Give a brief explanation for your choice. A paper appearing in The Journal of Pain (March 2010 , 199-209) described a study to determine if meditation has an effect on sensitivity to pain. Study participants were assigned to one of three groups. One group meditated for 20 minutes; one group performed a distraction task (working math problems!) for 20 minutes; and one group practiced a relaxation technique for 20 minutes. Sensitivity to pain was measured both before and after the 20-minute session.

Short answer

The study is an experiment because it involves manipulation of the variable of interest which is the activity (meditation, distraction task, or relaxation technique) performed by the participants and thereafter measuring the response (sensitivity to pain).

Step-by-step solution

Understanding Study Types

Observational studies and experiments are two types of studies in the field of statistics. Observational studies observe individuals and measure variables of interest without any interference, whereas experiments deliberately impose some treatment on individuals in order to observe their responses.

Analyze the Given Study

In the given study, participants were divided into three different groups where each group was made to either meditate, perform a distraction task or practice a relaxation technique. The study also mentions that the sensitivity to pain of each individual is measured before and after the 20-minute session.

Classify the Study

Given that the study involves dividing participants into groups and imposing different treatments on them (meditation, distraction, or relaxation), and then observing their responses (sensitivity to pain), it can be concluded that this study is an experiment. Experiments involve manipulation of variable of interest, therefore this study is not observational.