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 career in occupational therapy requires a master's degree for entry level, although many people also earn a doctoral degree. Therapists must pass an initial certifying exam given by the National Board for Certification in Occupational Therapy, and be licensed by their state. For instance, in New York, you must have completed an accredited Occupational Therapist Program earning an entry-level master's degree or post-baccalaureate certificate, finished at least six months of supervised field work, and passed the NBCOT with a score of 450 or higher.