A call-in poll is an unscientific attempt to measure public preferences by having radio or television audience members or newspaper readers call a telephone number and register their opinions. Usually a single question is posed, and people are asked to call one phone number in support of a viewpoint and another number in opposition. Call-in polls are used by some media organizations as a way to measure public opinion and get the audience involved. But they are very problematic from a data quality standpoint and should not be referred to as “polls.”

A major problem with call-in polls is that the participants are entirely self-selected. Only those people who tuned in to that particular broadcast at that time, or read that newspaper, can be included. ...