A TV station includes a poll as part of the nightly local news show. A provocative question of the day flashes on the screen and viewrs are asked to text their "yes" or "no" answers. Are these poll results representative of the local community opinion? Any potential sources of bias?

There is no indication of bias.

Under coverage bias is possible. Since only people watching that news program were polled, their answer my differ from the general population.

Response bias is possible. The study was conducted in such a way as to achieve a desired response that may be different from the population in general.

Unresponse bias is possible. Since people that do not watch that news program were not surveyed, the study may misrepresent the general population.