Random samples are used in population sampling situations when reviewing historical or batch data. The key to random sampling is that each unit in the population has an equal probability of being selected in the sample.
Individuals pursuing a career as an occupational therapist usually need to earn a post-baccalaureate degree from an accredited college or university or education deemed equivalent.  Education and training. A master's degree or higher in occupational therapy is the minimum requirement for entry into the field.
A doctoral degree is the highest educational level a therapist can achieve. While it is not required to practice as a therapist, you will have to get a doctorate if you want to become a licensed psychologist. A doctoral degree can also help you gain more knowledge and specialize in a particular area.