Comparing 2016 and 2020 survey modes

Live phone (RDD) polls are conducted by human interviewers with random-digit dialling. Live phone (RBS) polls are conducted with voter registration lists. IVR/online polls are conducted both online and with interactive voice recordings over the phone. Phone/online refers to polls that combine IVR and human interviewers.
THE GLOBE AND MAIL Source: aapor.org