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.
Your master's degree is where you will get the specialized training you need to become a licensed therapist. You will likely take classes in interpersonal, group, family, and child psychology, as well as classes on ethics in therapy, psychological theories, research methods, and clinical best practices.