Coaches are conducting a study to assess the impact of a new training regimen on athletes Athletes are randomly divided into two groups: the first group follows the new training routine, while the second group adheres to a standard regimen. Coaches observe the athletes for two months, after which they ask the athletes to provide feedback through a questionnaire regarding their response to the new training approach and any potential side effects they may have experienced. What is this an example of? A sample survey An experiment An observational study