Systematic random sampling. Systematic random sampling is done through some ordered criteria by choosing elements from a randomly arranged sampling frame. You can chose from every ânthâ element in a sample frame i.e. 10th, 15th, 20th and so on.
An associate or bachelor's degree is typically required to pursue employment as a diagnostic medical sonographer. Students also have the option to graduate with a degree in a related field, pursue a certificate program in diagnostic medical sonography and then receive on-the-job training.earn how to become a diagnostic medical sonographer. Research the job description, education and licensing requirements to find out how to start a career in medical sonography.
To become an oceanographer, you need a graduate level education, either a Master of Science (M.Sc.) or a doctoral degree (PhD) in oceanography, marine biology, biochemistry, hydrogeology or a closely related field.urther Training Needed to Become an Oceanographer. Although professional certification is not typically mandatory to be hired as an oceanographer, many practitioners choose to obtain certification voluntarily.